SDPaulS8

Have been trying to smog test our 2002 S8 and both shops I have taken it to have had probems doing the testing. Since it is all-wheel drive they can't run it on the dyno and need to maintain 2250-2730RPM for 30 seconds as part of the test with the car in park/neautral. After spending ~2hours trying neither shop was able to keep the RPM stabe in that range for the allotted time. The rpm will stay stable for about 5-7 seconds and then slowly surges out of the range. The acclerator is very sensative to throttle movements in this range at with the car in Neutral or park and even the smallest of corrections end up in ossilations in rpm taking the car out of range well before 30 seconds..

The car has 4500 miles, has been weel cared for and runs great when driven in the real world. Both shops and the dealer are baffled and not sure what to do. Anyone out there who has any experience or hints. Car is inside the 8year/80000 mile Federal emissions warrranty but out of the 7 year/70000 mile California emmisions warranty. Not sure how that will play out. Guess I can take it to the dealer and press them on the emmisions warranty and see what happens. Anyone out there with any ideas?

Thanks,
Paul
San Diego

audinutt

the techs needs to have the car in neutral and hold the brake pedal the entire time as I recall...
Someone else had this issue and then it was able to maintain the rpm to pass smog.

-Richard

SDPaulS8

Audinutt thanks for the suggestion.

The tech and shop manager at the smog shop (recommended by Audi)tried again for another 45 minutes and couldn't get past 19 seconds out of the 30 required. Used neutral and brake depressed along with high beans on to get a little load to work against. They were both had shaking legs and were ready to quit.

Had been practicing with the lead mechanic from the local dealership who had take a long look at it, checked and reset the throttle body, pulled fault codes and had spent his own personal time to figure out how to over come the SENSATIVE throttle. None of the trouble shooting did anything but with a lot of practice and luck we could eventually get 30 seconds. Way easier to use the tach in the car the display on the smog computer due to lag (makes it a two man operation).

They leg my fresh legs and mind have a crack at it. It took me 5 tries and another 10 minutes at the smog shop but got it to stay in the zone for the requisite 30 seconds. Passed cleanly with very minimal emissions well under max and now it's two more years before we have to worry about it.