My car is running really bad right now. It idles between 2 and 5 hundred rpms, and if I let it sit long enough (less than a minute) without putting my foot on the gas pedal, it will stall out. And while it's idling, its kinda surges up an down a little bit, and is really choppy, it kinda sounds like I have aftermarket cams. It's not throwing any codes, and I don't know if this is related or not, but the exhaust smells really bad. Thanks in advance for the help.