So Fix it

Most likely you have multiple oxygen sensors in your Jeep Cherokee. Figuring out which one needs to be replaced will be more challenging than actually replacing it. A code reader can condemn and position a particular oxygen sensor, but since the sensors average around $75 or more a piece, you might consider leaving the code reading up to a professional. Most parts stores that sell quality direct-fit oxygen sensors usually have code readers and can find out the information for you at no charge as long as you purchase the part you need from them.
Once you have the required information and tools, you can change the oxygen sensor on your vehicle.

Instructions

How to Change the Oxygen Sensor to a Jeep Cherokee

1

Locate the oxygen sensor that needs to be replaced. The very first sensor is in the manifold and can be accessed under the hood on the drivers side of the engine. The rest will have to be accessed from under the vehicle in the exhaust system. There is one at the rear of the manifold in the front exhaust pipe, another in the pipe going to the catalytic converter on the passenger side under the Jeep.

2

Raise the front of the Jeep if necessary by driving it up on car ramps. Apply the parking brake and place a wheel chock behind one of the rear tires. Crawl underneath on a creeper (if you have one) with the tools and the new sensor.

3

Put on the safety glasses.

4

Spray WD-40 on the threads of the oxygen sensor and allow it to soak in. Be caul the engine is not too hot when replacing the sensors, especially the very front one up in the manifold.

5

Follow the wire of the oxygen sensor to the plug and unplug it. You can use the screwdriver to press in and release the clip lock.

6

Remove the oxygen sensor with the oxygen sensor socket and ratchet. If it is stubborn, you may want to try and heat the pipe area up with the hand torch to expand the pipe. Once the sensor is loosed from the threads, allow the pipe to cool down if you had to use the torch.

7

Remove the old oxygen sensor.

8

Screw in the new oxygen sensor and make sure there is a coating of anti-seize lubricant on the threads. Most quality direct-fit after-market sensors will already have a coating applied to them. This will make future extraction a little easier.

9

Tighten the sensor with the socket and ratchet, but be caul not to over-tighten. If you strip the threads of the sensor, youre going to have to buy another one.

10

Plug the wire back into the plug.

11

Remove the tools and lower the Cherokee and/or close the hood.

When the Check Engine light comes on in your 2000 Toyota Camry, it may indicate a faulty oxygen sensor. Another indication of a failing oxygen sensor is a significant decrease in fuel mileage. If youre spending more time and money at the pump, check your oxygen sensors. The oxygen sensors in your Camry are located before and after the exhaust manifold, protruding from the exhaust pipes. Buy a new sensor from an auto parts retailer.

Instructions

1

Start the ignition of your Camry and allow the engine to run for approximately five minutes. Turn the ignition off.

2

Raise the front of the 2000 Camry with a jack and secure it on a set of jack stands. Remove the jack once the front of the Camry is supported on the jack stands so you can slide under the car.

3

Slide under the Camry and locate the oxygen sensor. Unplug the sensors electrical connector. Press the retaining clip and pull the plug out of the connection.

4

Remove the sensor with an oxygen sensor socket and ratchet. If the sensor in your Camry is secured with bolts, remove the two bolts with a socket and ratchet and pull the sensor straight out. Discard the old sensor and gasket.

5

Install the new gasket on the replacement sensor. Thread the sensor in by hand and tighten it with an oxygen sensor socket and ratchet or, if it is secured with bolts, install it straight into place and tighten the bolts with a socket and ratchet. Press the electrical connection together until it clicks.

6

Repeat the process on the other sensor if necessary.

7

Raise the car slightly with the jack to remove the jack stands. Lower the car to the ground.

There are a variety of components in the emission control system of modern automobiles, one of which is the Oxygen (O2) sensor. It measures the amount of oxygen present in the engine exhaust. The O2 sensor is linked to the Lexus SC400s computer, which then makes adjustments to the fuel/air mixture as the engine is running. This helps the engine run at peak efficiency, reducing exhaust pollution. The O2 sensor requires periodic replacement. Many owners can do the job themselves.

Instructions

1

Park your Lexus SC400. Set the parking brake, and open the engine hood. Let the engine cool completely before proceeding.

2

Locate the O2 sensor. Its in the lower engine area on the passenger side, threaded into the exhaust manifold.

3

Remove the wire from the sensor. Spray some anti-seize spray at the bottom of the sensor where it goes into the manifold. Let the fluid penetrate for a few minutes before proceeding.

4

Remove the sensor with the appropriate size socket and ratchet. Rotate the sensor counter-clockwise to loosen.

5

Install the new sensor into the hole and tighten firmly. Attach the wire and the job is finished.

Prior to the second phase of onboard diagnostics (OBD II), implemented in 1996, many vehicles (including the 1995 Chevrolet Astro Van) came equipped with a single oxygen sensor. This sensor was placed on the manifold or front exhaust pipe to monitor the mixture emitting from the exhaust. Emissions that indicated the engine was running vehicles too lean (too much air) or too rich (too much fuel) would trigger the sensor to communicate to the computer and set off the malfunction indicator lamp. In 1996, the number of oxygen sensors doubled or even quadrupled on vehicles in order to also monitor efficiency of the catalytic converter.

Instructions

1

Apply the parking brake on the Astro Van and then pull the primary hood release latch on the drivers-side kick panel.

2

Open the hood by releasing the secondary hood release latch and then support the hood with the hood prop rod. This will allow some light through the engine compartment for more visibility when changing the oxygen sensor.

3

Lift the front end of the van with the jack and then support it on jack stands placed under the concave frame rails in the front.

4

Put on the safety glasses, gather the remaining items needed and then crawl under the front of the van.

5

Locate the catalytic converter at the center of the exhaust system and follow the exhaust system to the front of the engine. The oxygen sensor is located on the front pipe, below the passenger-side seating area.

6

Spray the penetrating lubricant onto the thread connection of the oxygen sensor-to-front pipe mating surface. Allow a few minutes to pass for the spray to penetrate.

7

Follow the wire on the end of the oxygen sensor to the plug connection of the wire harness (about 8 inches away). Use the small, slotted screwdriver to unlock the clip retainer on the wire harness connection and then unplug the oxygen sensor wire from the wire harness plug.

8

Place the oxygen sensor socket onto the ratchet and align the wire of the oxygen sensor through the slot of the socket. Place the socket firmly onto the oxygen sensor and apply counterclockwise pressure to loosen it from the front pipe. Remove the sensor.

9

Inspect the new direct-fit oxygen sensor threads. Many come equipped with a light coating of electrically conductive anti-seize compound. If there is none on the threads, spread a light coating of the anti-seize compound on the threaded section of the oxygen sensor only. Do not get the compound on the electrode of the sensor.

10

Hand-thread the new sensor into the exhaust port on the front pipe and tighten using fingers as much as possible.

11

Tighten the sensor fully with the socket and ratchet. Only snug the sensor to the front pipe. The threads of the sensors are much softer than the port and can easily strip if over-tightened.

12

Reconnect the oxygen sensor wire to the wire harness plug.

13

Start the engine up and then crawl back under to check for any obvious exhaust leak coming from the oxygen sensor port. If necessary, tighten the sensor a little more until there is no leak.

14

Lower the Astro Van and release the parking brake.

The Camry is a mid-size car that has been manufactured by Toyota since 1980. The 1992 Camry has one oxygen sensor, which reads the amount of oxygen in the exhaust gases and sends the information to the engines fuel delivery system. That system then adjusts the amount of air and fuel being delivered to the engine, based on the reading. A faulty oxygen sensor can cause an increase in emissions and a decrease in fuel efficiency. Replacing the oxygen sensor is a relatively easy task that requires just a few basic tools.

Instructions

Removal

1

Open the hood and locate the oxygen sensor at the base of the exhaust manifold. You will see wires coming out of the top of the oxygen sensor.

2

Apply penetrating oil to the base of the oxygen sensor where it threads into the exhaust manifold.

3

Disconnect the engine wiring harness from the wiring on the oxygen sensor. Use a flat-head screwdriver to pry the connectors apart if necessary.

4

Place the oxygen sensor socket over the top of the oxygen sensor and turn the sensor counterclockwise. If you do not have an oxygen sensor socket, use an open-end wrench. Loosen the oxygen sensor and remove it from the exhaust manifold. Dispose of the old oxygen sensor by recycling it or returning it to an auto parts store.

Installation

5

Apply a thin coat of anti-seize compound to the threaded end of the new oxygen sensor.

6

Insert the new oxygen sensor into the exhaust manifold. Turn the oxygen sensor by hand to make sure that you dont cross-thread it.

7

Tighten the oxygen sensor with the socket or open-end wrench. Be caul not to overtighten the sensor.

8

Connect the new oxygen sensor to the wiring harness.

The oxygen sensors in your Toyota Tundra monitor the oxygen levels in the exhaust, thus helping regulate your trucks fuel consumption. If your gas mileage has decreased or your "check engine" light is on, the oxygen sensors may be the cause.

If you have a singe exhaust, your Toyota Tundra will have two sensors; if you have dual exhaust, your truck will have four sensors. Buy replacement oxygen sensors from an auto parts retailer or Toyota dealership.

Instructions

1

Disconnect the negative battery cable with a wrench and secure the cable away from the battery.

2

Locate the faulty oxygen sensor. There will be one sensor located in front of the catalytic converter and one located behind the catalytic converter, on the exhaust pipes. If your Tundra is equipped with dual exhaust, you will have four oxygen sensors, two on each pipe.

3

Remove the wiring harness from the oxygen sensor. The harness will simply unplug from the sensor, pulling free.

4

Remove the oxygen sensor from the truck. Your approach will depend on which Tundra engine you have: You can use an oxygen sensor socket and ratchet to unthread the sensor or a box-end wrench to remove the mounting nuts and pull it free of the exhaust.

5

Install the new oxygen sensor and tighten it with an oxygen sensor socket and ratchet--or replace the mounting nuts and tighten them with a box-end wrench, depending on your specific Tundra.

6

Press the wiring harness connector into the connection on the oxygen sensor socket. Repeat this process for the remaining sensors if you are replacing them all.

The oil pressure sensor, often erred to as the oil pressure sender, is a unit responsible for telling a vehicles computer the oil pressure. It controls the gauge on a vehicle, which lights up as a warning indicator. This signals that the automobiles engine is receiving too little oil pressure or the sending unit is faulty. Low oil pressure could mean that not enough oil is present and can be easily fixed with additional oil. It might also indicate that the engine is burning oil or that an oil leak exists. If the sensor, or sending unit as some call it, is to blame, it can be easily tested.

Instructions

1

Insert the key into the ignition, and turn the key to the accessory setting. The engine should not be running.

2

Look at the oil gauge on the dashboard. Unplug the wire that is connected to the sending unit, if the gauge is at zero. If the gauge goes up to three, it indicates that the sender is bad and needs to be replaced.

3

Hold the end of the unplugged wire from the sending unit, and touch it to the negative part of the battery or to any other metal piece in the vehicle. If it shows zero on the oil gauge, it is a good sender and is not faulty.

The oxygen sensor is an important part of the exhaust system. By sending periodic electrical impulses at different voltages, it informs the cars computer whether or not it burns fuel at its peak efficiency. When the exhaust has lots of unburned fuel in it, the oxygen sensor sends signals around .8 to .9 volts. When too much oxygen is getting pumped through and not enough fuel, the signals are .1 to .3 volts. The perfect air/fuel mixture is around 0.45 volts, and the CR-Vs computer strives to maintain that.

Instructions

1

Place a jack under the front of the frame of your Honda CR-V and lift it. Slide jack stands under the frame and lower the SUV onto the jack stands.

2

Lie on a mechanics dolly and roll yourself under the SUV. Find the muffler. It looks like an oval cylinder with piping running in one end and out the other toward the back of the car, where your exhaust gets expelled from the CR-V.

3

Follow the piping with your eyes from the muffler leading toward the front of the SUV to the catalytic converter. It is a circular cylinder attached to the underside of the car with two bands clamped around it, and it has piping running in one end and out the other. If you have difficulty, the diagram for the catalytic converters and oxygen sensors on 2 Car Pros can help.

4

Find the two sensors bolted into the drivers side of the catalytic converter. The one near the front of the SUV is the primary oxygen sensor, which measures the air/fuel mixture before the exhaust runs through the catalytic converter. The one located closer to the rear is the secondary oxygen sensor, which measures the oxygen content of the exhaust after it has gone through the catalytic converter. Be aware that the Honda CR-V has two oxygen sensors and either can cause error codes.

The Chrysler Concorde, also known as the sister car to the more popular Dodge Intrepid, came from the factory with two V-6 engine options; a 2.7-liter engine and a more-powerful 3.5-liter engine. Of the two engines, the 3.5-liter engine was noted for its increased reliability over the smaller engine, which was prone to oil sludge problems. To help control and monitor the engine temperature, the 3.5-liter engine contains a coolant temperature sensor, located on the thermostat housing at the front of the engine.

Instructions

1

Start the engine and allow it warm to operating temperature, which is 200-degrees Fahrenheit.

2

Locate the coolant temperature sensor on the top of the thermostat housing. Its mounted vertically and has two wires protruding from its base.

3

Disconnect the coolant temperature sensors two-wire electrical connector. Measure the resistance across the sensors two terminals with a digital multimeter; the specified value is 700 to 1,000 Ohms.

4

Let the engine cool down for three to four hours until the coolant is at room temperature. Measure the resistance again across the terminals with a digital multimeter. The resistance at 70-degrees Fahrenheit should be between 7,000 and 13,000 Ohms. If the resistance falls outside either of the hot or cold values, the sensor must be replaced.

5

Measure the resistance across the pin terminals on the sensors electrical connector. If the resistance is greater than 1 Ohm, replace the sensors connector.

If the gas mileage in your 1996 Ford Explorer has noticeably decreased or the engine is running rough, you may have a failing oxygen sensor. The 1996 Explorer uses four oxygen sensors in the emissions system. The sensors are located to the front and rear of the dual converters and mount straight into the exhaust pipes. You can easily change the oxygen sensors on your truck at home with a few common hand tools.

Instructions

1

Raise your Explorer with a jack and position a set of jack stands beneath it for support. Remove the jack once the jack stands are stable.

2

Disconnect the electrical connection from the oxygen sensor. Remove the oxygen sensor using an oxygen sensor socket and ratchet. Discard the old sensor.

3

Install the new sensor and thread it by hand. Torque the sensor to 30 pound-feet with a torque wrench. Press the wiring connection into place until it clicks.

4

Repeat the process on the remaining sensors if needed. Raise the truck slightly with the jack and remove the jack stands. Lower the truck to the ground and remove the jack.

Freightliner tractor trucks are used to transport goods around the country and for other heavy-duty tasks. Air pressure monitors are used to let the driver know whether or not the air pressure in one of the tires is too low for driving. If the Freightliner is driving on a tire in which the pressure is too low, the tire could blow. This increases the chance of losing control of the vehicle. You can troubleshoot an issue with your tire pressure monitor, but it will take a professional to replace it.

Instructions

1

Park the Freightliner on a level surface. The weight of the vehicle should be evenly distributed on all of the tires. Park near an air pressure machine, such as at a truck stop or large service station.

2

Go to the first tire on your Freightliner that you think may have a defective pressure monitor.

3

Make a note of the required pressure from the label on the tire. If you do not know the required pressure, contact the manufacturer or the tire retailer.

4

Turn the key inside the Freightliner to the "Accessory" or similar position so the electrical system turns on. The trucks dashboard gauges need to be functioning so you can get a reading from the pressure monitor.

5

Locate the valve stem on the tire and remove the cap from the stem. Use a small flat-head screwdriver to press down on the tip inside the valve stem to release the air out of the tire.

6

Wait until the tire is about halfway flat and then check the gauges inside your truck. The pressure monitor should be lit. Replace the pressure monitor if it is not lit. Replace the air removed from the tire.

When an oxygen sensor fails on your Toyota Avalon, the gas mileage of your car will noticeably decline. The Avalon oxygen sensor regulates the amount of fuel your car burns, and when it fails your Toyota burns more fuel than necessary.

Instructions

1

Locate the Avalons two oxygen sensors on either side of the catalytic converter on the exhaust manifold. The Avalons oxygen sensors look like a gold spark plug with a wire coming off the end.

2

Remove the Toyota Avalons wiring harness from the end of the both oxygen sensors using your fingers. Do not damage the end of the Avalons wiring harness.

3

Take out both of the Avalons oxygen sensors using the oxygen sensor wrench.

4

Apply the anti-seize compound to the Avalons two new oxygen sensors threads.

5

Install the Toyota Avalons two new oxygen sensors using the oxygen sensor wrench. Re-attach the wiring harness to the Avalons oxygen sensors using your fingers.

When your Isuzu Trooper begins burning more gas than normal or running rough, you may have a failing oxygen sensor. When an oxygen sensor begins to fail, it does not report the oxygen concentration of the exhaust properly and causes the vehicle to burn too much fuel. When an oxygen sensor begins to fail, the check engine light of your Trooper may illuminate as well. Buy replacement sensors at an auto parts store or Isuzu dealership.

Instructions

1

Raise your Isuzu Troopers front end using a jack. Position the truck on a set of jack stands.

2

Locate the two oxygen sensors along the exhaust pipe path. The oxygen sensors will be located before and after the catalytic converter and will protrude from the exhaust pipes.

3

Disconnect the wiring pigtail from the sensor. Isuzu uses a full pigtail on the Trooper, so you will need to follow the wiring down to the connection to pull them apart.

4

Remove the sensor from the exhaust pipe using an oxygen sensor socket and ratchet. Insert the new sensor carefully, threading it by hand to start. Tighten it with the oxygen sensor and ratchet.

5

Connect the wiring pigtail to the plug. Repeat the process on the other oxygen sensor. Raise the front of the truck and remove the jack stands. Lower the truck to the ground.

Depending on the year, make and model of your Ford F-150, the vehicle may have a temperature sensor and a sender: If the truck as a gauge, it will have both; if not, it will only have the sensor. The sender may be located in the radiator or near the thermostat housing. It reads and sends the temperature of the water/antifreeze mixture to the gauge. The sensor also sends the temperature of the water/antifreeze mixture to the computer, so that the computer can make adjustments in timing, air and fuel mixture, and other adjustments needed by the truck to run ai its optimum performance levels and get the best fuel mileage.

Instructions

1

Open the hood of the F-150.

2

Inspect the front, center of the engine and locate the rear of the thermostat housing. Find the thermostat housing by following the top radiator hose from the radiator to the block.

3

Place your hand on the sensor that is mounted in the intake manifold, just behind the thermostat housing. The sensor has a round plug, which has wires coming from the wiring harness plugged into it. If you remove it, the base will look like a large bolt that screws into the intake manifold.

4

Push the plastic harness connector out and lift the wiring harness plug out of the sensor. Using the socket, unscrew the coolant temperature sensor from the intake manifold.

5

Wipe a thin layer of anti-seize compound on the threads of the coolant temperature sensor. Screw the sensor into the intake manifold. Plug the wiring harness back in.

Oxygen sensors have been installed on Nissan trucks since the early 1980s. In 1995 and 1996, an additional sensor was added to monitor the catalyst efficiency. V-6 and V-8 engines in Nissan trucks can now have as many as three or four sensors. The upstream sensors are generally in the manifold(s) (two manifolds with V-6 and V-8 engines) or just below it. The downstream sensors are located just behind the catalytic converter(s). Its possible for a do-it-yourselfer to replace these sensors.

Instructions

1

Park the Nissan truck up onto two car ramps and apply the parking brake. Open the hood.

2

Place a wheel block behind one of the rear tires.

3

Crawl underneath the truck with all the tools and a pair of safety glasses on. Locate the sensor you need to replace.

4

Spray the threads of the sensor with a generous amount of penetrating lubricant and allow 5 to 10 minutes to soak in. Repeat this step if necessary.

5

Locate the wire harness plug of the oxygen sensor and disconnect it.

6

Use an oxygen sensor socket and a flex-head ratchet for upstream sensor removal or a 22mm box-end wrench for downstream sensor removal. Turn the sensor counterclockwise to remove it from the exhaust port. If using the ratchet and sensor socket, place the wire of the sensor into the slot of the socket. For the 22mm wrench, feed the wire through the wrench before placing the box-end side onto the sensor.

7

Screw the new sensor into the exhaust port. Most quality replacement sensors will have a slight amount of anti-seize compound on the threads of the sensors right out of the box. Dont get the compound onto the thimble tip of the sensor. If the sensor does not have compound on the threads, its recommended to put a little on them for future replacement repairs.

8

Tighten the sensor using the ratchet or wrench. Be extremely careful not to overtighten the sensor. The threads are very delicate and there are only four or five threads, so its easy to strip them out. Tighten them snug only. Plug the sensor wire back into the wire harness.

9

Remove the wheel block and lower the truck to the ground. Close the hood and drive the truck as normal. The service engine soon light will reset within 50 to 100 miles, or you can take it back to the parts store and have it reset for you.

All vehicles come equipped with small engine components called engine oxygen sensors. Many different types of oxygen sensors perform an array of different functions, and a faulty oxygen sensor can wreak havoc on engine operation and performance.

Rough Engine Idle

Vehicle engines that have a bad oxygen sensor often run irregularly or roughly. Oxygen sensors can control or contribute to many different engine functions, including fuel/air mixture, engine timing and engine combustion intervals. A faulty oxygen sensor can disrupt any of these things and cause a rough engine idle.

Engine Missing

A bad oxygen sensor can impede the air/fuel mixture of an engine or interfere with the engine combustion, both of which can cause an engine to miss, or run irregularly. An engine miss is normally most pronounced at idle or at lower engine speeds; a faulty oxygen sensor can inhibit the normal fuel delivery/combustion within an engine and cause a miss.

Engine Pinging

If a bad oxygen sensor is aligned with the ignition system on a cars engine, it can retard or advance engine ignition timing, which can cause an engine to ping. Pinging occurs when an engines combustion gases are ignited at the wrong times.

Poor Gas Mileage

Depending on the type and/or location of a faulty oxygen sensor, the fuel-delivery and the fuel-combustion systems can be thrown off or made irregular by a faulty oxygen sensor. If too much fuel is injected into an engines cylinders or a faulty oxygen sensor disturbs the delicate air/fuel mixture of an engine, gas mileage will suffer.

Increased Vehicle Emissions

Vehicle oxygen sensors play a critical part in keeping a vehicles emissions within certain parameters. A vehicle can fail a state-mandated smog test because a bad, or faulty, oxygen sensor will not accurately measure various engine ratios or air/fuel mixture concentrations or adjust certain engine operations accurately enough to keep a vehicles emissions in check.

Oxygen sensors monitor the oxygen saturation in your Ford Explorers exhaust. The fuel to air ratio is regulated based on the readings from the oxygen sensors. A failing oxygen sensor can cause decreased fuel economy. Improve your fuel consumption as well as your Explorers emissions by replacing faulty oxygen sensors. You can purchase a new oxygen sensor at an auto parts store or Ford dealership.

Instructions

1

Disconnect the battery cable from the negative battery terminal. Set the cable in a secure area away from the terminal.

2

Lift the truck with a jack and position a set of jack stands securely beneath it to support the vehicle while you work under it. Remove the jack when your Explorer is secure.

3

Locate the O2 sensors along the exhaust. Depending on the engine your Explorer is equipped with, there are anywhere from one to four O2 sensors along the exhaust pipes and the manifold. Change your O2 sensors one at a time to make the process easier.

4

Disconnect the electrical connection from the top of the sensor. The electrical connection plugs into the wiring pigtail on the top of the sensor.

5

Unscrew the sensor from the manifold or exhaust pipe using an oxygen sensor socket and ratchet. Discard the old sensor.

6

Coat the threads of the new sensor carefully with anti-seize compound if your new sensor is not pre-treated with it. Many sensors are pre-treated with anti-seize.

7

Install the sensor using an oxygen sensor socket and ratchet to tighten it securely. Attach the electrical connector to the pigtail.

8

Raise your Explorer with the jack and remove the jack stands. Lower the truck to the ground.

The oxygen sensors on your Jeep meter the amount of oxygen to fuel burning and communicate to the computer of the Jeep when there is a variance of rich or lean mixture. After a while, due to heat and age, the sensors break down and need to be replaced. Since your Jeep may have multiple oxygen sensors, telling which one it is and where it is will be up to you. Code readers can help determine a bad oxygen sensor and its location after it has tripped the engine computer and set off the "check engine" light. Youll need a few things to install one yourself, so have the parts store help you out in locating the right sensor and theyll most likely do it for free if you buy the parts from them.

Instructions

1

Put on the safety glasses and locate the oxygen sensor(s) that need to be replaced. Most Jeeps will have the very front oxygen sensor screwed into the manifold on the drivers side of the engine that can be accessed from the engine compartment. The other ones will be located in the exhaust system, again screwed into the exhaust pipes near the back of the manifold and near the catalytic converter. If youre on the ground under the Jeep and have a creeper, grab the tools and crawl under.

2

Follow the wire attached to the oxygen sensor to the plug. Press the clip lock in with a screwdriver and separate the oxygen sensor wire from the plug.

3

Place the wire of the oxygen sensor through the slot on the side of the oxygen sensor socket and place the socket onto the sensor. Attach the ratchet and try to loosen it from the manifold or exhaust pipe. Its not going to be easy. You may have to heat up the exhaust pipe or manifold around the threads of the oxygen sensor with the torch. Only heat up the threads on the pipe or manifold because if you heat the oxygen sensor as well, the metal in the sensor will expand along with the metal in the threads of the pipe and you will defeat the purpose. When the threads are nice and red, quickly apply the ratchet and socket and try to loosen it again. Once youre successful, allow the area that was heated up with the torch ample time to cool down.

4

Make sure there is a light coating of anti-seize lubricant compound on the threads of the new oxygen sensor. Most come with a light coating on them already. This will make future extractions easier. Screw the new sensor into the threads of the pipe by hand and be careful not to crossthread. Tighten the sensor with the ratchet and oxygen sensor socket. Do not over-tighten. There are only 4 to 5 threads on the oxygen sensors and although they need to be tight, over-tightening them can easily strip the threads of the sensor.

5

Plug the wire of the sensor back into the harness plug. Grab the tools and put them away. Start up the Jeep to make sure there is no exhaust leak coming from the oxygen sensor connection. To reset the "check engine" code, you can either wait it out for the Jeep to reset itself or take it back to the parts store and have them reset it. The computer will have to go through a series of the Jeep heating itself up to normal operating temperatures and cooling down in order to run through the IM monitors. It can take up to a few days or so many miles traveled to do so.

Replacing the knock sensor on the Nissan Maxima is simple, but the sensor can be expensive, so be sure to have the car properly diagnosed before assuming the sensor is bad. The knock sensor detects engine knock or ping in the engine, then transmits data to the engine-management computer, enabling the computer to retard or make other critical adjustments to the timing, spark and fuel delivery.

Instructions

1

Open the hood of your Maxima and locate the negative battery cable at the battery terminal. Using a wrench, remove the retaining bolt and separate the cable from the battery, isolating the cable while you work.

2

Locate the knock sensor on the top edge of the engine block on the right side of the engine. It is about halfway back and is a circular part with a bolt running through the center and an electrical connector on the outer edge. Disconnect the wiring harness connector from the knock sensor by lifting the locking tab slightly and then pulling the connector off the sensor.

3

Remove the bolt from the center of the knock sensor with a socket and ratchet, them remove the sensor from the engine block. Position the new sensor on the engine block and insert the retaining bolt through the center, threading it into the engine block.

4

Tighten the bolt with a socket and ratchet, then install the electrical connector on the sensor. Make sure you push the connector in enough for the locking tab to engage.

5

Connect the negative battery cable on the negative battery terminal. Install the retaining bolt and tighten it with a wrench. Close the hood of your Maxima.

A 1998 Honda Civic has two oxygen sensors: one between the catalytic converter and the exhaust pipe, and a second located behind the catalytic converter in the exhaust manifold. The purpose of an oxygen sensor is to monitor the oxygen levels in the exhaust. A bad oxygen sensor can cause the "check engine" light to come on. The engine may also run poorly and blow smoke out the tail pipe. Replacing an oxygen sensor is not difficult if you have right tools and time.

Instructions

1

Spray penetrating oil around the base of the primary oxygen sensor where it threads into the exhaust pipe. The oxygen sensor is located in exhaust components that heat up and cool down and may be difficult to remove. You will need to be under the Civic to access the sensor .

2

Disconnect the oxygen sensor from the wiring harness.

3

Place the ratchet and oxygen sensor socket over the top of the oxygen sensor. The socket has a slot for the sensor wires to pass through which allows you to loosen the oxygen sensor from its mounting collar. Turn the socket counterclockwise to loosen the oxygen sensor.

4

Remove the socket from the oxygen sensor when it has become loose enough to turn by hand. Remove the oxygen sensor and discard. Oxygen sensors contain precious metals and should be recycled properly or returned to an automotive store.

5

Install a new oxygen sensor into the threaded collar by hand and turn it clockwise until it is tight. Place the oxygen sensor socket over the top of the new oxygen sensor to fully tighten it. Connect the new oxygen sensor to the old wiring harness.

6

Spray penetrating oil around the base of the secondary oxygen sensor where it threads into the exhaust manifold. Remove the secondary oxygen sensor from the engine compartment.

7

Repeat Steps 2 through 5 to remove and install the secondary oxygen sensor.