So Fix it

Engage the vehicles parking brake, and put the car into neutral (for manual transmission models) or park (for automatic models).

Open the hood, and locate the EGR valve, which is on the intake manifold. After you have located it, start the car, let it run for five minutes, and then turn it off.

Remove the vacuum hose from the EGR valve. This hose is on the top part of the valve. Once you have removed the vacuum hose, replace it with the hose from the hand vacuum pump.

Use the pump on the hand vacuum pump to give 10 inches of vacuum to the EGR valve. Once you have done this, observe the EGR valves diaphragm -- a properly functioning EGR valve remains closed for 15 to 20 seconds with 10 inches of vacuum. If your valve takes longer to open, it is time to replace it because of leakage.

Connect the air compressor to the air tank with an air hose and two air hose fittings. Regulate the pressure of the compressed air released from the air tank with an air pressure gauge. Use the regulated compressed air with a pressurized air line and detachable fittings.

Drop a one foot length of light chain into the gas tank through the filler opening. Shake the tank to loosen and remove any rust inside the tank. Remove the chain.

Turn the tank upside down and shake vigorously. Attach a blower fitting to a pressurized air line. Blast the inside of the tank with pressurized air.

Seal the petcock opening on the bottom of the gas tank with an air hose fitting attached to a pressurized air line. If necessary, install a fuel petcock and fit the air hose to the petcock with a hose fitting and a flat head screwdriver.

Prepare a solution of 50 percent dish washing detergent and 50 percent water. Adjust the air pressure leaving the compressed air tank to 15 pounds per square inch above atmosphere.

Seal the gas cap and pressurize the inside of the gas tank to 15 pounds per square inch above atmosphere. Paint the exterior of the gas tank with the detergent-water solution using a paint brush.

Look for air bubbles. Any air bubble indicates a leak and a defective gas tank.

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

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.

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.

Visit your states inspection center. A routine part of each inspection is to test your vehicles emissions. The inspection sticker on your mirror will let you know when you are due to have your exhaust emissions and car inspected.

Wait for your car to be placed on the machine used by the inspection station for the test. An on-board diagnostic test and idle test are the tests used to inspect emission systems. The system is going to check how well your emissions system works and if its up to state standards.

Find out if your exhaust emissions have passed the test. The inspection station is going to let you know immediately whether your car meets the standards or not.

Take your car in for repairs if you fail. If your car fails the test, you need to go to an emissions repairman to fix the problem. Once the repair has been done, you can return to the inspection station to test the exhaust emissions again.

Find out if you are required to have a smog test. If your states DMV sends you a registration renewal notice that says that smog certification is required, or if you are selling your car or bringing it to a new state to be registered, you might need to get a smog test. Most smog tests are good for a couple of years, unless your DMV specifies otherwise.

Consult with the DMV to find out the requirements for smog tests. Most states require smog tests only if the car is of a certain age or make. Usually older vehicles will be required to take a smog test before they can be registered. In California, for example, vehicles that are six years old or less are not required to get an annual smog check inspection. Some exceptions may apply depending on the type of vehicle you want to register, for example, RV or other commercial vehicles may require a smog test.

Contact your DMV and make an appointment for a smog test. The DMV will direct you to an approved auto repair shop to schedule the smog test. Ask the representative or go to the local DMV website to find out about the requirements for passing the smog test, such as the emissions level that the smog test must not exceed.

Bring your vehicle to the approved auto repair shop for the smog test. The mechanic will provide you with a smog certification that you bring to the DMV to complete your vehicles registration.

Test your car shortly after starting it. You may be able to hear and feel the leak more easily while it is still cold. You also lower the risk of burning yourself.

Sniff around for exhaust. This is the least definitive way to test your manifold for leaks, but it may be a sign. Carbon monoxide, which is what is released by your exhaust system, has no smell.

Listen to your car. Most exhaust manifold cracks or leaks will cause a ticking noise, especially when your car is running cold. There may even be a noticeable vibration that goes along with the noise.

Use a stethoscope to listen to the manifold closely. You should be able to determine the location of the leak if there is one. If you dont have a stethoscope, use a hose or tube to localize sound.

Check your manifold physically. If you can get it out of your car and manually inspect the part, you may be able to determine warping or cracking. Since this requires removing parts from your engine, you may want to consult a mechanic.

Look for damage around the exhaust ports. Discoloration or burnt paint often signifies a leak. Burned spark plugs, boots or valves indicate a leak as well. If you notice this kind of damage, have your manifold fixed immediately to avoid more serious fires.

Take your car in for an emissions test, even if it is not due. Most leaks reduce the oxygen output and will cause the car to fail the test. If your manifold passes inspections, you may just need to have it straightened out due to warping.