i started using synthetic oil in my car this past week, and yesterday on a 1 1/2 hour trip i noticed a burning smell when i stopped. i drove home and when i got back i could still smell it but only when i was stopped. so i looked at it today and after drivin home from work i looked under the car and i saw a small amount of smoke rising off of my x pipe. it was right near one of the two 02 sensors (bassani high flow catted pipe). has anyone else had a problem like this. my car is a 2001 svt cobra, minor bolt on mods, intake xpipe, straightpipes and tuner, 68,000 miles, not abused but drivin like a cobra owner would drive a cobra. a napa guy said it could be a rear main seal goin bad, or possible a gear oil leak where the tranny and drive shaft meet? cant pinpoint the smell but def. a burning smell.