Hey everyone, about 450 miles ago I had the speedtuning ecu installed. the car has supersprint exhaust and k&n intake. the car FLEW. boost was excellent, as was throttle response, the car really felt great. as time went by, it began to loose the throttle response, and essentially by the 2nd tank of 93 octane, it felt like it had before the chip, except with more boost. the throttle response felt dismal.

removed the ECU today for about 20 minutes, and reinserted. drove car through rock creek park tonight, and the car literally flew on command - no problems.

does anyone know what is wrong here? no check engine codes - no problems whatsoever - but the performance loss during those 300 miles seemed significant! regardless, i was thinking it might be a bad front O2 sensor, or perhaps the MAF sensor is going - but wouldnt those reflect a check engine code?

any advice would be MOST appreciated.

-Jordan

98 S70 T5A
speedtuning 17psi
supersprint
k&n
brembos