I recently replaced a cracked manifold with a completely new one, I just put in new spark plugs a couple of months ago and am still having problems after the car has been in stop and go (turn engine on and off) conditions. Today after driving the car off and on throughout the day, it briefly lost almost all acceleration (maximum speed about 20-25 mph) and the check engine light came on. I pulled over and turned the engine off for about 15 minutes. I turned it back on and the acceleration came back as normal, but the check engine light is still on. Does anybody have any idea what this could be? Thanks in advance for you help.

 

Go to Autozone and pull the code. Let us know.