[Roadmaster9]

Hey, I have a really annoying problem with my 94 Lt1. It loses revs when I just barely give it gas between idle and about 1500 rpm. Once it's higher than that it runs perfectly fine, also idles completely normal, this ONLY happens when I step on the gas just enough to raise the revs slightly. It has been getting worse and has even stalled out on occasion. Since it runs fine in higher rpm and I have 4:10s on an A4 it's easy enough to ignore most times, but I want to fix it as I have to be obnoxious in a parking lot pulling out to keep the revs up and I'm sick of it. It started when I had a header gasket leak and I thought that when I fixed that I would go away, but it has stayed the same. Should I change my O2 sensors, bad MAF, etc? Looking for ideas on want might be causing it. Also, no check engine light on, if that would narrow it down. Thanks to the help.

 

[Roadmaster9]

Also, forgot to mention that this only happens in closed loop. It runs fine at all times in open loop.

 

[Roadmaster9]

Well, I finally figured out my problem. It was my egr valve gone bad. When my header gasket leaked and made it run rich, it fouled my egr valve (that and it already had over 180,000 miles on it). I thought it happened at closed loop, but upon further investigation, I discovered it only did it when it was hot, it ran good when it was cold started and for a few minutes until it heated up, which I mistook for it entering closed loop. When I would start it and run it after it was run not long ago and still warm it would still have the problem even though it was in open loop. Just wanted to post this in case anyone else ever has this problem. It drove me nuts.