i have a raven performance muffler on my car (fart cannon as called) and on the back of my car there is somthin building up on the car...i believe its oil?..also i have to put oil in my teg every 2k miles after my oil change. some one told me that it can be the pcv valve? i was wondering what every one else thinks. and how do i get that crap off my white teg!