Speed in idling mode: 750-1000 rpm.
Test for CO content in exhaust gases: 0.2-1.2% in the measuring tube.
Left: Testing the throttle potentiometer: What resistance readings you should get at the potentiometer terminals marked here can be seen in the table on the next page.
Right: Checking the injection nozzle and intake air temperature sensor. The illustration shows the location of the connections of the common plug.
In this diagram you can see the readings of the incoming air temperature sensor near the injection nozzle, as well as the coolant temperature sensor in the pipe on the left side of the engine (position "1" in the figure on the right). The illustration shows the resistance value of the sensor depending on the temperature.
If you have received other readings, you need to check the vacuum tubes and the electromagnetic valve of the fuel evaporation system and query the fault memory.
Special annual exhaust gas toxicity test
If you always have your car serviced at a workshop, you know that the exhaust gas toxicity test is part of the annual inspection anyway. But even if you service your car yourself, we recommend having this test done at an Audi workshop. There, the fault memory is read and erased from its memory, something that a regular workshop cannot do.