check engine light in 5th gear

[ariem]

Hello,

I have a 1993 90S 5-spd and I've noticed the check engine light comes on sporatically. The previous owner said it's the oxygen sensor. He also said he replaced two sensors already when he replaced the timing belt and catalytic converters.

I've noticed that the check engine light ONLY comes on when in 5th gear. So I thought, "hmmm". So for the last week I've tried to narrow it down to what is causing it. So I drove the car in city without going into 5th -- NO light! I drove it on the highway letting it rev to at least 3200rpm before upshifting -- NO light. In highway traffic, if I slow down past 50mph or so and then accelerate without goin back down to fourth the light comes on.

So, by my detective skills, I'm deducing that the check engine light is when I'm going to slow in 5th gear. Like there isn't enough power to bring the car back up to 70 or 80 mph. It'll do it but it's sluggish.

Am I just not that well versed in Audi engines or is it just a sensor or something that needs to be addressed???

thanks for any help any of you can be.

ariem

[TJ66]

Hello,

I'm curious my 1993 90s is experiencing the same issue w/the check engine light in 5th gear--what did you find out about this?

[ariem]

nothing yet. anyone know why the light is coming on?

[TJ66]

I'm curious, are you experiencing overheating possibly?

[ariem]

no, im not getting overheating. Just the engine light. what I also notice is it comes on when my speed drops in 5th gear below 60 mph and I hit the gas once traffic picks up. but i never have that issue in any other gear (accelerating in too high a gear)

[Blinded]

hmm. i dont seem to have the same problem but after a prolonged drive (2hours or so) going a decently quick speed 90-120mph average, i get the check engine light until i let the engine cool down more...