i`m thinking of painting my muffler flat black , i know to use a high temp. paint but my question is will it stink all the time and will it leave a black soot on my bumper ?

 

I don't know about the smell, but I doubt you'd get any "soot" or black discoloration on your paint from it. I'd be more concerned with soot from the actual exhaust

 

My friend flat blacked he catback straight pipe a while back, and I really couldn't smell any paint burning or what not. Just make sure to get the High Heat BBQ or engine bay paint and make sure to let it dry completely before really heating the thing up. Try and find the highest temp rating you can, I've seen 500 degree (will flake off eventually) all the way to 1200 and 1500 degree paint. I'd go with 1500 if you can find it.