Check exhaust system for leaks

On vehicles with a regulated catalytic converter, leaks in the exhaust system upstream of the lambda sensor can cause the following faults:

• Starting difficulties; engine stalls, shakes at idle, stutters during acceleration.

• Start the engine and check the exhaust system for leaks by holding a rag over the exhaust tailpipe. Have an assistant check all sealing flanges for escaping exhaust gas (hissing noise, gas flow felt by hand).

• Spray the joints between cylinder head/manifold and manifold/front exhaust pipe with a commercial leak detection spray and check for bubble formation.

• Eliminate the leak.

1. 1

   Front exhaust pipe

2. 2

   Lambda sensor

On most models, it is screwed into the exhaust pipe further forward than shown in the illustration.

1. 1

   Catalytic Converter

2. 2

   Center and rear muffler

Mufflers must be replaced together, as they are not available individually as spare parts.

1. Exhaust manifold

1. 1

   Lambda sensor

2. 2

   Catalytic Converter

3. 3

   Muffler

Note: The illustration shows the exhaust system of the 1.6 l engine. The front exhaust pipe of the 1.8 l engine looks similar to that of the 2.0 i engine.

1. Exhaust manifold

1. 1

   Lambda sensor

2. 2

   Catalytic Converter

3. 3

   Muffler

The exhaust system of the diesel engine looks similar to that of the petrol engines; the front exhaust pipe is bolted to the turbocharger.