I just bought a 2000 GT with only 77,000 miles on it. The car is clean with the exception that it won't go above about 3000 RPM. There's no check engine light on and rides fine otherwise.
+1 on above. Double check that the "check engine" light isn't burned out. Remember there is a "lamp test" for all lamps at initial key on.
Is this an automatic or manual? If automatic, are there any issues with the shift lever? Might be handy to confirm that the PCM knows the correct shift state. IE, if the PCM thinks the transmission is in neutral when actually in drive, this would limit the RPM's.
Drove it to work today and found that if I don't put the pedal to the floor it will accelerate. It seems like a fuel issue. If I downshift and get on the gas at about 3000RPM it acts like I'm hitting a governor.
Replaced the fuel filter today. Will see if that helps at all tomorrow.
Had a problem similar with our 01, filler neck had rusted and dumped rust in the gas tank, pump sock was clogged starving the engine for fuel. Eventually it got so bad the car would stall. This did not give a check engine light.