I have an 01 318. Recently the engine started popping and sputtering, but it never stalls. When I stand on it the misses from the engine basically stop, but as soon as it reaches a cruising speed it will periodically pop and sputter. I have changed the plugs, wires, dist. cap, rotor, throttle position sensor and have ran the codes, which indicated a vapor leak. I had a smoke test done and found no leaks. The engine has 112,000 miles on it and I have installed a cold air intake. Also when I start it up it will idle fine for a few minutes, and then right on cue, it will make a sound like a jet engine revving up and then it will idle very rough, with the truck shaking from the rough idle. I am at a loss and have been told that this is very common to this truck and no one really has been able to help me out.

 

O2 sensor maybe.

 

Sounds like possibly a combination of a bad IAC and front 02 sensor, but that's just me.

 

One can always try cleaning the IAC and TB. Remove negative battery cable before doing so, remove it if replacing the o2 also. https://dodgeforum.com/forum/dodge-r...n-the-iac.html

 

Would either of those thrown a code?

 

Nope, not always.

 

+1 on the TB and IAC cleaning, cheapest fix first.

 

I have tried the TB and IAC already to no avail, I am going to disconnect the O2 sensor tomorrow and see where that leads me.