Loss of Power, backfiring - 1991 90 20vq sedan

[theringmeister at triad.rr.com]

Brendan,
I'm going to venture a guess and say that when you pull the codes you'll find your throttle potentiometer has either met its match or is on its way out.  I had a similar issue in my cq years ago, but I found my throttle pot laying on the heat shield for the headers.  It worked its way out of the mounting on the underside of the throttle body.  There's a great bit of info at 20v.org regarding pulling codes.  You might find it a little more difficult than pulling the seat belt bulb out of it's socket and installing it in the check engine position like I did on my cq, but there's still a relatively easy way to do it without VAG-COM.

Since you've already changed your O2 sensor, which would have been one of my first guesses, I'll only ask if you replaced it with an OE (correct plug) or generic (splice) sensor.   I'm not going to go into why I think it's worth it to buy the OE sensor, but suffice to say I didn't go the splice route.


--
Wylie Bean
TheRingmeister at triad.rr.com
90 cq
91 90q20v sport
92 UrS4
01 allroad