20,000mils and the car is burning one quarts every 500mile or so...the car all ready had its first oil change and is still burning oil, the car also has a thick layer of black soot in both of it's exhaust pipe. i try wiping it off but if keeps on building up...my theory is that the car is pasting oil and it burning in the exhaust and that the build i keep seeing. i've not seen the car produce blue smoke as of yet so my theory could be wrong but were is all the oil going the i keep putting in ? if any has a solution to my problem...HELP...also can the passing of oil through the exhaust system mess up or destroy the O2 senors and cat. converter? (im thing long term)