The Mysterious Stalling 97 A6

My brother has a 97 Audi A6 2.8. It seems to have developed a strange stalling problem now that the temperature has warmed up.

It will start and idle OK, the problem only really happens when the car is in park or neutral, not drive. Then, all of a sudden, just stall. No stumbling, no rough running of any kind. It seems the warmer the car is, the quicker it stalls.

The car is stock, no check engine light or idiot lights of any kind. Now, he recently installed a K&N air filter. Could that cause this problem? Maybe if some of the oil from the K&N got onto a sensor ( I'm thinking MAF sensor) it could cause this problem without tripping the check engine light? Maybe a bad 02 Sensor somewhere and unrelated to the K&N?

Any ideas or thoughts are appreciated. The car has 101k miles and is a US model.

I had a problem similar to your problem. I found that I had two problems instead of one. One was that I had a code 16815. That told me that I had bad cats, also I had a pinch EGR hose which was part of the problem too. I found the cat's at usaimportparts net at a good price and fix the pinch hose and gave the car a good fuel injection cleaner I like LIQUI MOLY or TECHRON. My problem has gone away and I hope this will help you with yours.And Good Luck

Thanks for the reply in this apparently dead thread. I will pass on the information.