I just recently picked up a '91 RX7, it had been wrecked about 10 years ago, fixed, then parked. The car seems to run good now, but i'm having a problem of a power surge, but only when driving at a constant speed, it also throws the CEL, but as soon as i let off of the pedel, the light goes back off. it usually takes about 10-15 seconds for it to do this at a constant speed. I dont even have a clue where to start on this problem.

if you can pull the mil codes then that would help im not too sure on s5 stuff

Like I said, the light goes off as soon as you let off of the pedal, so it doesnt stay on.

yea i know see about getting it checked cause it could be something that its seeing but not storing