So Fix it

Catalytic converters, also called "cats," absorb exhaust heat, and should, ideally, be as close as possible to the exhaust manifold for emissions compliance. This placement varies by make and model and can have a significant impact on performance.

The Y-Pipe

V-type engines often use y-shaped pieces of tubing to join the cylinder banks exhaust streams before entering into the converter. Converters are often bolted right to the back of this Y-pipe.

Direct Connection

Many manufacturers, such as Honda and Toyota, are becoming known for bolting the catalytic converters right to the exhaust manifold outlet, with nothing in between.

Down Tubes

Most turbocharged engines use a down tube, which is a smooth piece of tubing that allows a turbos exhaust flow to move away smoothly, before encountering the restrictive cat.

Oxygen Sensor

All new vehicles have an oxygen (O2) sensor somewhere between the exhaust manifold and cat. This works in conjunction with an after-cat O2 sensor to notify the engine control computer of any converter malfunction.

Exhaust Brakes

Large diesel trucks often have a large valve in between the cat and manifold, known as an exhaust or "Jacobs" brake. When closed, these valves create back pressure in the engine and allow a driver to control downhill acceleration without using the foot brake.

An engines exhaust manifold routes exhaust gases from the engine to the vehicles exhaust system. Without the exhaust manifold, hazardous exhaust fumes can reach the interior of the vehicle. Installation of the exhaust manifold is usually the final step of the engine installation process, but installation is also necessary when an exhaust manifold gasket is replaced. Thankfully, installing an exhaust manifold is a straightforward process.

Instructions

1

Ensure that the exhaust manifolds mating surface is free from old gasket deposits to begin the installation process. Old exhaust manifold gaskets rarely leave gasket deposits, but if any deposits are present they should be scraped away with a gasket scrapper.

2

Place a new exhaust manifold gasket over the manifolds mating surface. Do not apply gasket sealer to this gasket.

3

Position the exhaust manifold with its gasket against the portion of the head where the manifold attaches, then place one exhaust manifold bolt through one end of the manifold and into the head. Turn this bolt only until it begins to grasp the threads within the head.

4

Insert another manifold bolt into the opposite side of the exhaust manifold and turn this bolt only until it begins to grasp the threads within the head.

5

Insert the remaining exhaust manifold bolts through the manifold and into the head.

6

Tighten each exhaust manifold bolt to the required torque specifications with a torque wrench to complete the installation. Refer to the vehicles specifications manual for this torque setting.

Exhaust flex pipes are a flexible metal pipe sections that are used either in areas where an exhaust pipe needs to be flexible, or to repair a damaged exhaust system. While they are all-metal, it is common for one to fail and require replacement.

Construction

Automotive exhaust pipes get extremely hot from the exhaust gas passing through the system and out the tailpipe. Due to this, when an exhaust system needs to bend, shift or be flexible, the manufacturer cannot use traditional materials like rubber. The flex pipe is made of metal strips woven into a lattice, and thus can withstand exhaust gas heat. Higher quality flex pipes will be made of stainless steel.

Use

Automotive engines move slightly during operation, whereas most exhaust systems are fixed from the mid-section back. Flex pipes allow the engine to move and not crack or rupture what would otherwise be an inflexible metal exhaust pipe. Flex pipes are typically found where the exhaust manifold meets the downpipe or mid-section of an exhaust, which is closer to the engine than to the exit tailpipe.

Availability

Exhaust flex pipe sections are widely available at automotive stores in a variety of lengths and diameters.

Seeing a vehicle with open headers is far less common than the majority of vehicles equipped with a full exhaust system. Open headers are extremely loud, potentially illegal on public roads and most commonly used on a race track. Open headers are the optimal design for exhausting engine gasses.

Exhaust Design

A full exhaust system is made of multiple components, which release gasses exhausted from an engines combustion chamber. Starting at the engines cylinder ports, an exhaust manifold or headers direct exhaust into a front pipe that leads into a catalytic converter, which acts as a filter. Exhaust then heads into a muffler, where engine exhaust sound is muffled, and finally it releases through a tailpipe. Open headers directly exhaust gasses from the engine through piping pointed outside.

Performance

Open headers provide optimal exhaust flow and velocity while minimizing back-pressure, which smothers engine power because of the direct path from engine to the air.

DMV & Emission Testing

The Department of Motor Vehicles sets vehicle requirements that vary by state. Open headers are often illegal because harmful exhaust gasses are not filtered and delivered straight into the air. Open headers will fail emission testing. There are exceptions. For example, Delaware requires every vehicle originally equipped with a catalytic converter to have one.

Certain motorcycles always emit some type of fumes upon starting the engine. However, grey smoke signals a problem with the engine and necessitates prompt investigation to avoid serious engine damage.

Clogged Air Filter

A clogged air filter causes dark smoke to come out of the exhaust pipes. If this is the cause of the smoke, then the bikes spark plugs will also not work. Change the motorcycles filter to remedy the situation.

Open Starter Plunger

An open starter plunger can also result in grey smoke from motorcycle exhaust pipes. The starter plunger is a small component of the starter. Repair this problem by removing the bolts from the starters cover to reveal the component. Push the plunger closed and replace the starter cover.

Float Bowl Fuel Levels

Grey smoke can result from improper fuel levels in the float bowl of the carburetor. Remove the float bowl from the carburetor by taking out the screws. Check the markings on the float bowl to ensure the fuel levels are correct.

Fumes created by your automobile during fuel burning are expelled from the engine by the exhaust system. The exhaust pipe, or tailpipe, is where fumes exit the car. Many car improvement jobs involve replacing rusted or broken pipes. It is important to know the exact diameter of the pipe that fits the rest of the exhaust system when replacing it. This process is complicated by the location of the exhaust pipe, and often by its angle of cut on the pipes end.

Instructions

1

Raise your car using a car jack to a height that will allow you to lie comfortably underneath the vehicle.

2

Open the clamps of your caliper, and place them around the outside of the exhaust pipe. Choose a portion of the pipe that is straight. Close the caliper clamps around the pipe securely, but not tight enough to dig into the metal of the pipe. Record the reading on the calipers on a piece of paper.

3

Stick one clamp arm of the caliper inside the end of the tailpipe, leaving the other clamp arm outside the pipe. Close the clamp around one wall of the pipe, measuring the pipes thickness. Read the caliper and record this number.

4

Multiply the pipes wall thickness by 2. Subtract this number from the total outside pipe diameter determined in Step 2. This remaining number is the inside diameter of your exhaust pipe. The full equation is:

Inside Diameter = Outside diameter - (2*Wall Thickness)

In the 100 years of the motorcycles existence, it has seen many changes. The Shovelhead motor, named for the shape of the top of the motor, has received a lot of use in those years. Changing out the exhaust system can increase performance and change the tune of exhaust note, giving you a different riding experience. Installing an exhaust on a Shovelhead motor isnt difficult, and can be done within an hour or so with the right tools.

Instructions

1

Install the allen key socket onto the 3/8-inch ratchet and extension, then unbolt the stock exhaust system from the engine. You may need to use a 3/8-inch universal joint to get around the tubing in some sections.

2

Unbolt the exhaust from the frame of the bike at the end of the tailpipes using the 3/8-inch ratchet and socket. Place the exhaust system to the side of the vehicle.

3

Mount the new exhaust system onto the motorcycle and bolt the new exhaust to the motor using the allen key socket on the 3/8-inch ratchet and extension. You may need to use a 3/8-inch universal joint to get around the tubing in some sections.

4

Bolt the pipes of the exhaust system to the frame of the bike using the factory hardware and the 3/8-inch ratchet and socket. Start the bike and listen for any exhaust leaks. If you hear some, tighten down the exhaust system on the engine again.

While manufacturers engineer engine valves to withstand their Faustian environment for years on end, even slight spikes in operating temperatures can damage these components. The exhaust valves get the worst of it, since they have to pass thousand-degree gases with only milliseconds of respite to cool down between each cycle. There are several easy ways to burn a valve.

Instructions

1

Reduce the amount of fuel injected and cause the mixture to go lean. Lean air/fuel ratios are probably the single most common culprit behind burned valves. Engines arent designed to burn all of the fuel they inhale; a large portion of it exits the cylinder unburned. Leaning out the air/fuel ratio allows more of the fuel to burn, which increases power and fuel economy (to a point), but it also increases the temperatures inside the cylinder. A clogged or malfunctioning fuel injector can also cause a cylinder to go lean, as can an improperly-tuned computer or carburetor.

2

Slide a huge camshaft into the block. After the exhaust valve picks up heat from the combustion chamber, it has to shed the heat into the cylinder head. A certain amount of this thermal transfer occurs through the valve stem, but much of it takes place while the valve remains shut against the valve seat. A big camshaft keeps the valves open longer, decreasing the amount of time they spend in contact with the cylinder head, and thus the amount of thermal energy they can shed during each cycle.

3

Dont install an exhaust manifold or exhaust headers. Old-school wisdom may have it that an engine needs exhaust back-pressure to function, but this is about as true as saying that people have to hold their breath to live. The reason that engines need an exhaust manifold is that the exhaust valve stays open after the piston starts moving downward in the cylinder. Without a manifold, the exhaust gases would shoot out and the piston would suck oxygen in from the outside and into the chamber, causing the mixture to go lean.

4

Advance your timing excessively. Odds are that excessive ignition timing will result in premature detonation (knock or ping) before it does a burned valve, but sustained high-rpm usage combined with excessive timing can easily damage the valves. This is especially true if you combine a bit of extra timing with a large cam and a lean air/fuel ratio, as some hot-rodders are apt to do.

5

Allow your engine to overheat and wear out. All the valve-to-seat contact time in the world wont save your valves if the coolant is either too hot to carry away thermal energy from the head or is absent entirely. Worn valve guides are another potential trouble spot, since the valve stem needs constant contact with the head in order to remain cool.

Adding a custom exhaust to your car is a good way to gain horsepower and a more aggressive tone to the exhaust at the same time. You could go out and buy a bolt-on system for your Altima, but if you want to truly customize, youll have to step up and have an exhaust built for you. First, though, youll want to find out what size your Altimas exhaust tubing is. That way you have a baseline to use as you determine how much you want to go up.

Instructions

1

Lift the Altima using the jack and place it on jack stands at all four corners. Make sure there is enough room for you to crawl underneath the car.

2

Locate the section of exhaust tubing that you want to measure. Open the calipers and place them over a straight section of exhaust tubing. Then tighten down the caliper until it contacts the exhaust all the way around.

3

Read the dial or digital gauge on your caliper to find out the approximate diameter. Exhaust tubing sells in average sizes: 2.25 inches, 2.5 inches, 2.75 inches, and so on; there are no odd sizes. Round the number on your caliper down to the next quarter size down, and thats your exhaust tubing diameter.

The corrosive effect of accumulated moisture, vibration and impact damage from road debris makes eventual muffler and exhaust pipe replacement a foregone conclusion. Depending on the model year and the exhaust configuration of your Chrysler 300---dual or single tail pipes---replacing the exhaust pipe involves disconnecting the exhaust pipe from the catalytic converter, loosening the hanger brackets that support the exhaust system and removing the mufflers and exhaust pipes from under the vehicle.

Instructions

Exhaust Pipe Replacement

1

Set the emergency brake and chock the rear wheels with wood blocks. Then, jack the car up on a hard, level surface making certain that the lifting point is a load bearing part of the car chassis and that the vehicle is high enough off the ground to allow easy access to the exhaust system. Position jack stands under the appropriate chassis contact points and ratchet them up to just touching. Now, slowly lower the car onto the jack stands.

2

Position the jack under the muffler and raise the jack to support the muffler before releasing the exhaust pipe from the chassis hangers. Double-check that you have purchased the correct replacement exhaust for your Chrysler 300 model. The typical configuration will have a catalytic converter in the exhaust line on each side of the block feeding by way of a cross-over pipe into a single muffler.

3

Disconnect the oxygen sensors from the exhaust pipe ports near the catalytic converters. Unscrew the two nuts on each U-bolt connecting the exhaust pipes to the back of each catalytic converter. The catalytic converter is the cigar-shaped emissions control device installed in the exhaust system, closest to the engine. Unless you have experienced a loss of power, can smell a sulfur odor or feel heat radiating from the car floor, your catalytic converters are probably okay.

4

Inspect the two mufflers for rust. If the exhaust pipes are rusted badly, the mufflers are ready to be changed, as well. With the car jack positioned under and against the larger muffler, the one closest to the motor, disconnect the exhaust pipe brackets from the support hangers and lower the entire assembly to the ground. To loosen rusted nuts and bolts, apply liberal amounts of WD-40. Give the penetrating oil a few minutes to soak in, then remove the nuts. If the pipes are rusted into the catalytic converters, rap them with a hammer to break the rust loose, but make sure that you are wearing safety glasses when you do this.

5

Assemble the new mufflers and exhaust pipes, on the ground, using the four new U-bolts provided to secure the pipes in each muffler port. Use the old assembly as a guide and compare them side by side for proper length. If you purchased an original equipment manufacturer replacement, the new assembly should fit properly. Check the hangers and hard rubber noise dampers for wear, and replace if necessary.

6

Position the new unit under the car and use the jack to raise it into position. Then, reattach the exhaust pipe brackets to the hangers and reconnect the exhaust pipes to the catalytic converter with two new U-bolts. Dont forget to tighten all the connections and reattach the oxygen sensors. When youve done this, jack up the car, remove the jack stands and slowly lower the car to the ground.

Mazda completely redesigned the Miata for the 1999 model year with a completely different look. Many enthusiasts were relieved that Mazda left well-enough alone underneath. The 1999 Miata still used the same 1.8 liter four-cylinder engine that was used in the first-generation cars. The stock single-exhaust pipe is attached to a cast-iron exhaust manifold that is bolted to the engine. A cracked manifold will allow exhaust gases to enter the passenger compartment and should be replaced immediately.

Instructions

1

Spray penetrating fluid on the heat shield retaining bolts, the exhaust manifold-to-engine block bolts, the EGR pipe fitting and the exhaust pipe-to-manifold bolts. Allow the fluid to soak in overnight, if possible.

2

Loosen and remove the nut and bolt that secures the factory shock tower brace to the drivers side shock tower with a socket and ratchet. Lift the brace straight up to allow access to the exhaust manifold. Skip this step if your car did not come equipped with the shock tower brace.

3

Loosen and remove the retaining bolts for the windshield washer reservoir with a socket and ratchet. Lift the tank straight up and move it to the side -- as far as the connections will allow -- to provide access to the heat shields on the exhaust manifold. Skip this step if your car is not equipped with anti-lock brakes.

4

Loosen and remove the retaining bolts on the air cleaner housing on top of the engine with a socket and ratchet. Loosen the clamp that secures the air intake hose to the air cleaner housing with a Phillips screwdriver. Pull the hose off the housing. Push the housing to the side to allow access to the heat shields and exhaust manifold. Cover the ends of the intake hose and its fitting on the air cleaner housing with clean rags to prevent foreign debris or dirt from entering.

5

Loosen and remove the retaining bolts that attach both of the heat shields to the exhaust manifold with a socket and ratchet. Remove the heat shields from the manifold and place them aside.

6

Remove the EGR tube retaining bolts on the exhaust manifold and the intake manifold with a socket and ratchet. Loosen and unscrew the fitting that attaches the EGR tube to the end of the exhaust manifold with a tubing wrench.

7

Loosen and remove the three bolts that attach the exhaust pipe to the exhaust manifold with a wrench.

8

Loosen and remove the exhaust manifold-to-engine block retaining bolts with a socket and ratchet. Work slowly to avoid damaging or breaking off the bolts in the block. Stop and apply more penetrating fluid, if one or more of the bolts seem very tight. Allow the fluid to soak in for several hours, if possible.

9

Pull the manifold away from the engine block. Note that the water pipe bracket will slide off one of the manifold mounting studs as you remove the manifold. Do not allow the water pipe to move rearward. Remove the manifold from the engine bay. Remove the exhaust manifold gasket from the engine block. Scrape away any gasket residue on the mounting surface with a gasket scraper.

10

Position a new exhaust manifold gasket over the mounting studs on the engine block. Position the replacement exhaust manifold over the mounting studs. Push the water pipe bracket over the stud that it was originally attached to. Replace and tighten the manifold retaining bolts to between 29 and 33 foot-pounds with a torque wrench.

11

Replace the exhaust pipe-to-manifold bolts and tighten them to between 32 to 44 foot-pounds. Tighten the EGR tube fitting into the end of the manifold to between 24 and 34 foot-pounds. Replace and tighten the remaining EGR tube retaining bolts.

12

Replace the heat shields and tighten the retaining bolts. Place the air cleaner housing into position and tighten the retaining bolts. Remove the rags from the intake hose and air cleaner housing. Push the intake hose onto the housing and tighten the hose clamp.

13

Replace the windshield washer reservoir -- if your car has ABS -- and tighten the retaining bolts. Push the shock tower brace -- if your car is so equipped -- into position and replace and tighten the retaining bolt and nut.

There are two schools of though regarding optimal efficiency for an exhaust pipe. Some would argue that an exhaust pipe should be short because of its aesthetic appeal. The other school of thought argues that longer tailpipes are better because they provide greater power curves and more overall engine power. There are two pieces of information that you must obtain in order to calculate the proper length of an exhaust pipe for your vehicle.

Instructions

1

Determine the center RPM values for your desired power curve. In other words, what will be the RPM amount for your average speed in the car? In general, motorcycles will be between 4000 and 5000. Cars will be between 650 and 800.

2

Calculate the opening point of the exhaust valve. The opening point is recorded in degrees before bottom dead center (BBDC). The default valve opening for a motorcycle is 43 degrees. The default opening for a car is 90 degrees.

3

Plug the two values into the exhaust length calculator program from the resources section of this article to get your result.

Properly implemented, either single or dual exhaust systems can perform well on most any truck. The question largely comes down to matter of perence in sound, appearance and budget.

Horsepower

Horsepower is a matter of exhaust flow, and it matters little whether that flow issues through one big pipe or two smaller ones.

Sound

Because dual pipes split the flow, it is easier to hear the sound of individual cylinders firing. Many people per some sort of dual exhaust for their more analog exhaust note.

Budget

Most people who replace a trucks exhaust system will opt not to use a true dual exhaust system, because often the entire system must replaced, from exhaust manifold to tailpipe.

Velocity and Torque

If there is one good argument for dual pipes, it is that using two smaller pipes will cause an increase in exhaust velocity, which may help boost torque for towing.

Turbodiesels

Almost all turbo-diesel trucks work best with a single large exhaust pipe, since the turbo only has one large exhaust outlet anyway.

Exhaust systems are regulated by the government. Many states emissions tests require that the exhaust system, including the muffler, is fully functional and efficient. The muffler is one of the easiest portions of the exhaust system to monitor--either it is working or it is not. You can repair the muffler to address some issues, but you must replace it to fix most problems. A quick troubleshooting session can help determine what action is necessary.

Instructions

1

Turn the vehicle off. For added safety, if the vehicle was recently run, allow it time to cool down because a muffler tends to get hot during operation.

2

Jack the car up high enough to see under the rear, following your manuals jacking procedure instructions.

3

Verify that the muffler is attached to the exhaust pipe. If it is not, take it to a local welder or exhaust shop to have it reattached.

4

Inspect the muffler to ensure it is whole and the mufflers body does not have visible holes or dents.

5

Replace the muffler immediately if there are signs of damage. Obtain a new muffler from your local parts store. With the rear of the car still jacked in the air, locate brackets that are holding the muffler in place. Loosen the brackets and slide the muffler out towards the rear of the vehicle.

6

Slide the new muffler into place, just as the previous muffler was. Utilize the mounting brackets to tighten the muffler back into place. Lower the car by releasing the jack slowly. Start the car and observe the muffler to ensure that exhaust is exiting the muffler port.

The exhaust on a car or truck directs the gasses built up from the internal combustion process out to the back of the vehicle, that way the gasses dont build up inside of the vehicle and cause a carbon monoxide poisoning. If you develop an exhaust leak, then not only will it make an annoying noise, but if it could leak exhaust gasses into the cab which could be dangerous. To fix the issue, you can use a specialized clamp called an exhaust clamp to fix the issue.

Instructions

1

Put the vehicle on jack stands with the jack. Start the engine and listen to locate the exact spot of the exhaust leak, then turn off the engine.

2

Crawl under the car and go to the exhaust leak. Wrap the clamp around the leak, which should not only be a hole, but should also have carbon buildup around the hole, indicating where the leak is.

3

Tighten the clamp down over the exhaust using the flathead screwdriver, making sure that its secure all the way around. Lower the vehicle off the jack stands with the jack.

Leaking exhaust at the engine on the 6.0-Liter GMC engine means the exhaust manifold gasket is faulty and there no longer is a good seal between the exhaust manifold and the cylinder head. To fix this leak, it is necessary to remove the exhaust manifold and replace the gasket. The exhaust manifold is secured to the cylinder head with six bolts.

Instructions

Removal

1

Lift the vehicle hood. Ensure the exhaust leak is coming from the mating surface between the cylinder head and the exhaust manifold, not the EGR valve or where the manifold meets the down pipe. Mark each spark plug wire with the paint marker to identify which wire belongs on what spark plug.

2

Turn each spark plug boot about a half turn and pull it straight off the spark plug. Do not remove any plug wires from their respective coils.

3

Remove each exhaust manifold mounting bolt with the proper size socket and ratchet. Gently pull the manifold away from the cylinder head a bit and remove the faulty gasket from the cylinder head.

Installation

4

Hold the new exhaust gasket to the exhaust manifold. Press the manifold and gasket to the cylinder head. Hand-tighten each exhaust manifold bolt.

5

Tighten the exhaust manifold bolts to 10 foot-pounds of torque with the proper size socket and torque wrench. First torque the inside bolts, then the two outside bolts. Once all of the bolts are torqued to 10 foot-pounds, repeat the same process to 15 foot-pounds of torque with the socket and torque wrench.

6

Install each spark plug wire by pushing it onto the proper spark plug. Pay attention to the marks previously made so the firing order is not disturbed. Shut the vehicle hood. Check the exhaust manifold bolt torque after the engine is warmed and cooled twice to ensure they maintain 15 foot-pounds of torque.

Cat-back (a.k.a. "catalytic converter back") exhaust systems are a popular add-on for enthusiasts seeking an increase in horsepower, fuel economy and torque. Additionally, these systems can add personality to any car by making the exhaust note deeper, louder and overall more aggressive. The fact that cat-back exhaust systems do not affect emissions in any way has made them a universally accepted mod in every state in the union.

Definition

An exhaust system has between five and eight basic parts, depending on the car. The system starts at the exhaust manifold(s) or header(s), which combine the exhaust output of the individual cylinders into one port (called a "collector"). The collector can connect to a mid-pipe (which links the manifold and converter) or can feed directly into the converter itself. Everything after that is the cat-back portion, which includes the crossover (on dual-exhaust, V-configured engines), the main tube section and the muffler(s). Some exhaust systems use one or more small intermediary mufflers (called "resonators") in the main pipe to deepen and smooth the exhaust note.

Power Benefits

When it comes to the cat-back, most original equipment manufacturers (OEMs) put far more emphasis on noise level and production cost than engine note and performance. The original pipes (especially on older cars) are often too small to allow exhaust to flow as freely as it could, and stock mufflers can be a significant impediment to exhaust flow. Almost any cat-back system will enhance power, torque over a stock system. These benefits can range from 1 to 2 horsepower on four cylinders to 30 to 40 on large engines with restrictive exhausts.

Fuel Economy

With all the emphasis manufacturers place on fuel economy, it might seem surprising that they dont just install larger exhaust systems in the first place. Cat-back systems help the engine to run more efficiently, which is always good for at least a small boost in fuel economy. Turbodiesel engines generally stand to gain the most; 10 percent improvements in fuel efficiency are not unheard of when used with a freer-flowing air filter.

Design

Aftermarket cat-back systems are generally made of large and free-flowing "mandrel bent" tubing, which doesnt have the flow-inhibiting kinks that most stock systems do. Many dual exhaust systems incorporate an X-pipe crossover to balance exhaust flow for increased horsepower and a smoother-sounding exhaust note. You have a choice of higher flowing fiberglass or steel-packed mufflers (such as those that originally came in the car) or "chambered" mufflers that often yield a quieter and lower exhaust note.

Sound

Although you might be tempted to buy the thinnest and lightest exhaust system on the market, youll probably regret it. Engines (particularly small ones) produce a whole spectrum of high-frequency sound, which vibrates the system and causes it to act like a giant speaker. This "drone" sounds bad and is certain to drive you insane with migraines. Thicker, larger diameter pipes will contain the exhausts high frequency sound and promote propagation of more pleasing low-frequency soundwaves.

The exhaust system on a truck helps to direct the exhaust gases away from the engine bay and safely out the rear of the vehicle. Since exhaust gases coming out of the engine are extremely hot, its best to work on the exhaust system only after the truck has completely cooled down. Over time, most exhaust systems---unless they are stainless steel---will rust or corrode, especially if you live in the northern hemisphere, due to the corrosive nature of the salt and sand that is frequently spread across the roads in winter months to melt ice and snow. Once the rust or corrosion happens, youll have to take off the exhaust system. But youll also need to know how to install an exhaust on a truck.

Instructions

1

Place the new exhaust system on top of the jack stands so that the entire exhaust is raised off the ground. If your truck does not sit high enough off the ground, youll need to simply rest the exhaust system on the ground while you work. Make sure the exhaust is oriented so that the catalytic converter or converters are toward the front of the vehicle and the muffler is toward the rear.

2

Slide the exhaust system onto the hangers underneath the truck that are attached to the body. The hangers are composed of a metal hook with a rubber loop. The new exhaust will have a metal hook also. Youll need to slide the metal hook on the exhaust system through the rubber loop attached to the bodys metal hooks.

3

Install the O2 sensors into the exhaust using the O2 sensor tool and socket wrench. The O2 sensor will thread into the exhaust like a bolt, and youll need to turn it clockwise to tighten.

4

Plug the electrical connectors into the O2 sensor(s).

5

Place a gasket over the end of the exhaust piping, and bolt the exhaust piping to the exhaust manifold on the engine.

6

Turn on the truck and check for any exhaust leaks. You will be able to visibly see any exhaust gases leaking from the connection at the exhaust manifold. If there is a leak, separate the exhaust piping from the manifold, and readjust the gasket or replace it with a new gasket.

The exhaust manifold is a large metal block bolted to the side of the engine, and it connects the exhaust pipe to the main engine block. To locate the exhaust manifold, trace your exhaust pipe to where the round pipe bolts to a two-bolt connection near the engine. The solid structure to which the pipe is bolted is the exhaust manifold. Installing a manifold requires careful torquing of the bolts.

Amount of Torque

Every vehicle has different levels of torque necessary to properly tighten its bolts. The standard is to use 20 to 30 foot-pounds of torque. Older engines often fall on the lighter side of the equation, so use 15 to 20 foot-pounds of torque if your engine is 15 years old or older. Some manifolds house different sensors and plugs, such as a check valve or exhaust plug. The different elements require less torque than the bolts on the manifold. Use between 10 and 17 foot-pounds of torque for those elements. The precise torque for your vehicle can be identified in the vehicle-specific repair manual, available from an auto parts retailer.

Torque Sequence

Clean off any used gasket material, and install a new gasket when you take the manifold off the vehicle. Torquing the bolts properly requires following a set pattern. The pattern helps the new gasket sit correctly against the engine blocking leaks. Hand-tighten all bolts initially. Torque the bolts in sequence to half the amount of torque necessary. Start with the middle bolts, and work your way toward the edges one bolt at a time. Repeat the process using the full torque necessary.

Additional Information

In most vehicles, the manifold is covered by a heat shroud, which is a simple piece of formed aluminum. The metal acts as a heat damper to prevent excessive heat from bouncing around in the engine. You must remove the heat shroud before working on the manifold. When installing the shroud, use 10 to 12 foot-pounds of torque. You also should inspect the length of the exhaust pipe for damage. When servicing the exhaust, you should disconnect each bolted connection, clean the surface of the connection and install new gaskets at each joint. You can unbolt each connection and separate the joint by several inches without removing the unit from the vehicle.

Motor vehicle exhaust systems are all either welded or clamped into place. Each has its benefits and drawbacks; some parts will require one or the other.

Types of Exhaust

Auto exhaust systems typically come from the factory welded together. It is with the replacement of pipes, mufflers and catalytic converters that you will see clamps put into use, though some new cars will come with a combination of clamps and welding. The customization of exhaust systems will also result in frequent clamp use, as will older model vehicles mainly because they have had parts changed.

Benefits of Each

The benefits of welding are the complete seal and prevention of leakage that it provides. This reduces pollution and improves engine compression and possible rattle. Clamped exhaust systems make it far easier to replace parts when necessary and remove the cutting and welding elements from the equation.

Considerations

The drawback to welded exhaust systems, especially when it comes to replacement parts, is the potential for cracking should the weld not be done perfectly. The main drawbacks to clamping are the imperfect seals that are formed, the potential for loosening and the loss of compression and pollution into the air.

Combination Systems

Exhaust elements near to the engine including catalytic converter often require welding because of the high pressure exhaust they withstand due to their placement. Clamps tend to be used at the back end of the car.