My bird has a problem: after ive been driving it around for about an hour, and it gets hot, it wont go to redline. At about 4-5k rpms, it will start to stall out and miss badly. I already replaced the coil, o2 sensors, and the plugs and wires are relativly new. The longer i drive it without giving it a rest, the worse it gets. This is a bad problem cause the track is 45 min away, and i can never get a good run in becuase it always starts to miss! The problem has gotten worse since the weather has warmed up. Please Help!!

NOTE: the cars temp is fine, it doesnt overheat

 

Sounds ignition related to me.

The opti acts kind of like a rev limiter when it's not getting a good reading- you get on it and the farther above 3k you go the more the tach starts swing around.

It could also be the coil, or a problem with the fuel system. Time to do some diagnostics.