Checking the condition of the exhaust system (Audi A4 B6)

1. The check should be done with a cold engine, so it is best to do it before the first trip of the day or no earlier than three hours after turning off the engine. Check the condition of the entire exhaust system, starting from the engine and ending with the end of the exhaust pipe. Ideally, this check should be done with the car lifted on a winch, when there is free access to it from below. If a winch is not available, jack up the car and securely place it on supports.

2. Diesel engine: Remove the lower engine cover, refer to Section Removal and installation the upper engine cover/lower engine compartment protection/subframe.

3. Check pipes and pipe connections for signs of leaks, severe corrosion and damage. Check the condition and reliability of all brackets and hangers in the system.

4. At the same time, inspect the underbody of the car for holes, corrosion, loose seams, and other defects that could allow exhaust gases to enter the car's interior. Seal all openings with a suitable sealant.



5. Shine a light on the exhaust system and inspect it for holes, rust, and chafing.

6. If there are severe dents, replace the exhaust pipes.



7. Check all rubber holders by turning and rotating them for cracks and replace if necessary



8. Petrol engine: Check the electrical connections and secure fastening of the lambda probe.

9. Diesel engine: Install the lower engine cover, refer to Section Removal and installation the upper engine cover/lower engine compartment protection/subframe.

10. Inspection of the inner surface of the exhaust pipe allows you to determine the current operating condition of the engine. The composition of the deposits in the pipe indicates the quality of the engine settings. If the pipe is black and sooty on the inside, this may indicate that it is necessary to thoroughly check the fuel system.

11. Lower the car onto its wheels.

[The text is based on materials from the website AudiManual.ru]