Ever since I did my exhaust, my car bogs. This only happens once every 2 startups or so and only happens for a few seconds then its fine for the whole rest of the time. (I.E. when it does occur, it will not reoccur unless the car is turned off) Another important fact is that it doesnt happen when cold. This led me to believe there is a problem with the egr valve, but I havent thrown any codes. After a few days of driving, back and forth to school couple of miles, the rear bumper and taillights get covered in soot. My exhaust tip doesnt stick out far enough from the bumper and it does burn some oil but not enough to make this much buildup. Any other ideas other then the egr valve, I wont have time to work on it till the weekend just wanted to get some input?