I have a 2002 Trailblazer that just had a bad thermostat replaced after months of it being stuck open and two days later the car suddenly idles rough and at around 50-55mph seems to lose power. The only code being thrown is for camshaft position sensor electrical fault but that was thrown way before this happened and I put a new sensor in it after thinking it may have been the problem but when I try to do the relearn procedure the car will not Rev up to the 5000rpm mark needed for the procedure. I put on a new clean throttle body but that didn't fix anything ethier.

 

 

The tool I use says 5200 rpm and I did it successfully before but now that it's idling rough the engine won't go above 4000 rpm so the process fails

 

 

Not sure was going to say throttle body but you say you either put a new one on or cleaned the old one . Did you pulled fuses 10 and 28 for 30 minutes after the throttle body cleaning , this resets pcm which is needed.

 

Yes did that but still the same. I have heard it could be a bad catalytic converter.

 

I see you replaced the camshaft sensor...now try this little item.ACDELCO12615873Variable Valve Timing (VVT) Solenoid / Actuator