Changed the spark plugs plug wires runs rough at idle hard start up smooth wow on the highway banging shift between first and second gear changed fuel system control module no change

 

DIAGNOSING MISFIRES

 

Changed O2 sensor today censor one bank oneHave a misfire cylinder five and seven. I also have two broken manifold bolts one bolt is in between five and seven cylinder and the other broken bolt is on the front opposite side. Should I change the manifolds and should I change the motor mounts with them same time?

 

What manifold? Intake ? Exhaust? Why replace it? Is it cracked in half or something?

Why do you want to change motor mounts? are they broken? it won't fix the misfire.

Just change your broken bolts and go from there.

 

From what I’ve been told the exhaust manifold should be changed when you have broken bolts it’s because they Could be warped. They suggest changing the motor mounts when you change the manifolds . I suppose they believe the mounts could be worn flexed too much allowing the bolt to break on the manifold. Mechanic keeps insisting that the bolt doesn’t break for no reason. I think the suggestion was to stop and exhaust leak before the sensors. I just asked questions about my truck and these are the answers I get. It was also suggested To move one of the coils from five or 7 to 1 or three to try and find a misfire which now he says is not random he feels the misfire could follow the bad coil and show up on his scanner.