My car exhaust seems to get a bit excessively stinky any time I hit lift, which I dont know if thats quite normal. It doesnt really smell like exhaust but more like theres some bad seals or something, and I've had people complain about it if they're behind me. My engine has 64k miles on it and a few weeks ago I misshifted and caught it at about 8500-9000RPM. I'm all stock with the BV valve removed and my exhuast unbolted at the axle. Is this something to be concerned about?