Starfire

When my car is idling I here what sounds like a misfire but it's very faint you can hear the normal exhaust note and then what sounds like a deep 'poom, poom' kind of sound, it's random and not very loud but it's definitely there. I don't throw any codes, and got new plugs and fuel filter, it it just me over listening? When you here the sound you can feel it to if you are sitting int he car, like I said its not loud and it's from the front of the car the engine seems to idle fine and can't hear any misses? Any ideas?

socalwrench

Well, I can get a popping sound from my muffler deletes- especially when it's cold. That's just the exhaust pressure equalizing.

I would watch the tach when you hear that sound- is there a change in RPM?

I mean, there's not much valve overlap with the factory cams that could cause the 'poom-poom' sound- like the erratic idle of the past muscle cars.

Starfire

Nope RPM is smooth

Got GT?

I had a similar problem in my '06 GT that was fixed after I took it to the dealer to get some TSB work done. The TSB said that some of the fuel pumps that were OEM caused air bubbles to form at the top of the pump, and the hesitation would give me the "bump" you were referencing. The dealer swapped out the pump and the problem was gone forever.

Starfire

Yeah but I don't really feel a hesitation, when I'm driving it runs fine, it just sitting at idle that I hear it.