We have a basic stage4 /vf30/utec and lately it's throwing a cel-#4misfire. Under very light load, it throws a cel but if i let the engine warm up fully(sitting at idle for a few minutes), there would be no cel. The car also idles intermittently rough and smooth when the AC is on. And when the AC is on, we get a flashing cel every once in awhile. I have changed plugs (the old ones looks ok).

The car runs fine otherwise I think. The only thing that changed since all this started were some chewed up wires leading to the back of the car from a critter that got trapped in the car.

Could it be a bad maf/o2 sensor? Anyone having the same problems? There a thread on the other board but no one has a definitive answer. I thought I would try it here.

May be it's time for a new sti block....

sigh....BlueMax