Wont Rev Past 4k

I have a 2000 2.4 4 cylnder grand am with 140,000 miles. The problem is it will not rev higer than 4 k rpm. Every time it reaches 4k the rpm cuts out.
no codes were found when scaned and somtimes the car will run normal for a few days.:icon16:

When does this happen, number one?

The rpm cut out constantly at 4 K rpm exactly when driving or in neutral. it did run normal for 2 days then when i started it in the morning the problem returned.

Well first off in "P" or "N" your car wont rev past what its governed for, keeps you from blowing the motor.

If its doing it when you are driving then you need a tune up. Or have other ignition components bad, ie coils, ICM, plugs or the boots.