Tips for working with the exhaust system (Audi A4 B6)

Good welding on rusty metal will not work, so repairing a rusted exhaust system usually gives only a short-term effect. Although an exhaust system repair kit and bandages allow you to somehow repair the system, the metal soon deteriorates near the repair site. In exhaust systems with several mufflers, it often happens that a few months after replacing one of the mufflers, the other muffler fails. For this reason, workshops usually replace the entire exhaust system at once. However, it is not necessary to replace the entire kit; carefully inspect the system and only then decide whether to replace the entire system or its individual parts.

When installing the fastening sleeve, make sure that the end of the bolt does not protrude beyond the lower edge of the sleeve.



Replacing the exhaust system is made easier by the markings on its parts. For example, if you are replacing the muffler outlet pipe 1, you must cut it at a right angle at the separation point using a special saw. The new pipe 3 is pushed up to mark A. The cutout in the pipe must be aligned with mark B. The clamping screw 2 is tightened to a torque of 25 Nm.





1. Place the car on trestles in such a way that it is vibration-resistant. After all, the car should not tip over when you rotate or pull the pipes with force.

2. If any bolt connection does not loosen during disassembly, strip the threads. Be sure to use new bolts and nuts when installing.

3. To be on the safe side, also replace the rubber holders.

4. If a part of the exhaust system has already been replaced, it is best to disconnect the detachable connections at the end of the pipes when they are hot. In workshops, a welding torch is used for this, but a propane gas torch can also be used. When doing this, be sure to have a fire extinguisher at hand. If you do not have a gas torch, try using rust dissolving agents.

5. The pipes are separated by means of strong rotational movements or hammer blows.

6. If this does not help, cut the pipe connection of the faulty muffler at a distance of 10 centimeters behind the place of connection. Cut the rest of the pipe lengthwise with a metal saw and break it with a powerful screwdriver.

7. If you lubricate the threads with heat-resistant copper grease during installation, the bolted connections will be easier to loosen next time. The same applies to pipe connections.

[This publication is borrowed from the resource audimanual]