It throws a code for lean fuel trim bank 1, but will clear itself. Anytime it rains or gets to 70 degrees or lower outside I get a harsh vibration that I can feel through the steering wheel at idle and the code will eventually reappear(it has thrown a random misfire code instead 1 time) I will get a minor fluxing of the rpm’s when I first start it up at times as well. Mechanics can’t figure it out. I’ve replace the fuel pump, had at least one of the o2 sensors replaced and cleaned MAF, no obvious air leaks and I’ve checked the hose under the resonator. This is an engine swap with another 3.7, so is possible that the computer needs reflashed? Other than that it runs amazing especially while driving. Any advice would be appreciated (sorry Doc Olds if I did this wrong, I’ve looked through all threads with no help)

 

retorque the intake manifold bolts.
also if the gaskets where reused or not installed properly your issue can also happen. you can also check your engine grounds incase of looseness or corrosion.

 

I’ll give it a try!

 

Yes, it may be necessary to do that but I'd replace the o2s with oem . Both upper and lower. That fact that the problem arises with temps and moister leads me to believe you have something else altogether going on though. Dampness and cool reek havoc on wiring.

 

I forgot to mention with the reflash question that one of the o2 sensors still reads even if the o2 sensor is removed(I can’t remember which one the mechanic said it was, upstream I believe) thank you for your help!

 

This is the items to cover. Acts like it wants to stall/rough idle -No CEL -What To Do: