It's rougher when it's cold, for sure, but it does it always. It does surge or anything, it just idles rough and in no particular pattern. I have noticed a lot of what sounds like valve chatter, and an airy sound, but its nearly impossible to hear over the engine. One thing I did notice is a fuel leak where the fuel line connects to the fuel rail. Its always leaking and although I changed out the quick disconnect and o-rings, it still leaks. I suppose it's possible that is the entire problem right there. There is also a hissing from the fuel tank area when idling. Not sure if this is related, but it maybe part of the puzzle. Also, yes I cleaned the throttle body, but I have yet to tackle the senors. Honestly, it seems like a kind of daunting task.