exhaust or maybe engine??

[BeatDaSHO]

well i start my car and i can hear like a kind of "putter" every 4 or 5 seconds. the tach doesn't move or anything. i can just hear it in the exhaust. I have the dynomax exhaust system and i already know i have a leak because i can hear it while i'm driving. will this cause a little "putter" when trying to idle? could it be something with the engine? I've already tried resetting my idle program per SDPatt's way so that shouldn't be a problem. Please help. Thanks.

Greg