Alright so I have a 95 GMC Jimmy, recently new engine with complete tune up, after a few months it still sounds like it has a misfire, and I don't know why, there are no codes that say so, the only two codes are P0441 and P1441 (I know what they are), would these make it seem like it has a misfire? You can see the engine shake a little bit too...?

while Im here might as well say that the gas pedal has some vibration to it, any ideas there?

Thanks for ya'll help!

 

The older cpi engine is known to have problems with no codes associated. Was the "new" engine a 100% complete engine or did you swap over your intake and fuel injectors over to the new engine?

 

Swaped over the intake and injectors...