Tikiman12

Hello everyone,

When I'm cruising down the highway between 75-80mph (17-1900 RPMs) my 2005 A4 vette starts a random misfire, the car stumbles. If I give it gas it stops happening, if I let it happen as much as it once the car will eventually come out of overdrive and drop into 4th and stop the stumble. That is the only time I get a flashing check engine light.

Finally got the check engine light to stay on and I got these 3 codes:
P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1 ECM
P0300 Engine Misfire Detected ECM
P2119 Throttle Closed Position Performance ECM

Things I have tried:
Brand new spark plugs
Replaced the MAF (I had an extra)
-These fixed the car for about 24hrs with out a misfire then it started happening again-

Crowhater

I went though this last year and they replaced darn near everything under the hood. I have scans and screen shots of it, the shop tried to fix it with parts changing but in the end after dumping the tune and doing a retune about 10 times it finally went away. They tried different cold air intakes, injectors, changed all the sensors, added grounding straps, plugs, coil packs, had GM import the updated program, etc, etc. It did not matter if I was in S or D, cruise control on or off. It took 3 months and they even tried to do a speed density tune. Looking back I wish they would have installed a new CPU and installed my tune. I am no expert but it seemed like a glitch in the CPU that finally went away. If you send me your email address via PM I will send you my scans and screen shots when I get back to the office on Friday.

DOUG @ ECS

By what you have described here I would replace your left front 02 sensor.