Q: Why do I have black soot on my exhaust? Check Engine is not on 2004 Mercedes E320

Hello - a bit of black soot on the exhaust pipe can be due to several things that don’t necessarily represent a problem. If you consistently drive short trips, where the engine doesn’t have a chance to warm up completely, or if this is a condition during winter weather when the engine intentionally runs with a richer fuel mixture, some black soot will accumulate on the tailpipe. Modern automotive electronics are really good at protecting the catalytic converters, so you should get a warning (via the Check Engine light) if there is any problem that threatens the converters. A good "freeway blast" work wonderfully to clean out any soot - Happy Motoring!