Hello,this problem has been posted before by somebody else . I have installed a WAI and 1.8ecu but the problem was there before. At about 4800+- rpms the car kind of spudders (almost like its having trouble) but at about 5100+- it seems to go and be just fine. I have replace the spark plugs incase of a misfireing but still no luck. mine is an auto if that makes any difference.Thanks for your help in advance.

 

I don't know much about auto trannys, but my guess would be it's not going into high gear well. Tranny could be close to done, or it might just need a fluid change

 

you should try your wires if those haven't been changed lately.

 

Sounds like the classic TPS problems. Verify your TPS manufacturer.

 

definatly check the TPS. If it is bad, it can send all sorts of weird signals to the computer