My 03 1500 4.7 Ram is giving me fits. We done a top end on it about a week ago cause I had a leaking head gasket. Ever since we finished it now it wants to die when I come to a stop after driving it down the road for a little ways and acts like it has a big cam in it like an old school chevy. I had a code come up so I checked it and it said mismatched VIN which I don't understand that. When we put it back together we triple checked the timing before putting the timing cover on and as far as would tell it was in time. Any ideas on what might be my problem to help me fix this would much appreciated.

 

post the code may help someone with your issue for advice , also check for vacuum leaks around the intake