Here my story, I wanted to change my Crankshaft Positioning Sensor, it broke off in the engine (mind you the car was working fine). So, I took it to pep boys, took them 2 days to get it out and new one. They ran a diagnostic they came saying the My fuel pump is going need to change it the car will not go above 30 mph. I found it strange since I just came from NC without a problem. fast forward when I get my car the RPM could not go above 2500. I could get a speed no higher than 70 mph. took it to a friend they first said it needs a tune up. It did, replaced the ignition coils and spark plugs. they then said it was my engine mounts replaced them. but my problem got worse now the cranks in two turns, and I found that this manifold tuning valve actuator when we move it, it changes the way the car starts. also now the car will not move out of 1 st gear. and now it will not go over 30 mph. I gave you the jist the last are the problems now. I do know the actuator cannot be replaced unless I purchase a new plenum. if someone sell it separate or can it be fixed. if you need more information I can tell you more.

 

If you are seeking help to figure out what is actually going on, I would suggest that you give pertinent info like mileage and computer codes that make the check engine light come on. But for the 30 mph speed and not shifting, the computer has put the car into "limp" mode. So there is something serious that the computer is reading from the engine's sensors.