k guys. I bought this car from my buddy for $200. It's a 98 lx. He turned it into a dirt track car. It has a problem though. When it is cool it runs fine and revs to the redline. When it gets warmer it starts running like crap and won't Rev past 4500 rpms. If you shut it off and start it back up it'll run good for a few minutes. Any thoughts?

 

When the PCM goes to closed loop there is a problem detected and limits rpm.
Check for any stored codes with an OBDII reader.

 

Like stated...check for codes. But I would pay special attention to the O2 sensor. I am assuming it has a normal exhaust installed.