Checking idle speed and exhaust gas analysis

With Mono-Motronic injection, adjustment work is unnecessary because there is nothing left to adjust in this system.

The control unit corrects idle speed as necessary. Recheck idle speed or CO content only in doubtful cases. Test conditions: engine at operating temperature, all electrical consumers switched off, and ignition timing correctly set. Specifications:

Idle speed: 750–1000 rpm.

CO content test in exhaust gas: 0.2–1.2 % at the test pipe.

If you obtain other values, check the vacuum hoses and the evaporative emission control solenoid valve, and read out the fault memory.

If you always have your vehicle serviced at a workshop, you know that the exhaust emission test is in any case part of the annual inspection.

But even if you service the vehicle yourself, we recommend having this test performed at an Audi workshop. There the fault memory is read out and erased, which an ordinary workshop cannot do.