muffler, straight through vs. chambered
I always let any car get to operating temperature before making the engine really work.Second off, I would get a strait through, although I can not say if it will solve your problem. Magnaflow would be my choice over flowmaster. I had a magnaflow on a previous vehicle and the exhaust was top notch.
Do what the others have said; warm your car up before you get on it. This may be why it's like this now.


