XTS running rich fuel mixture?
My wife came in the other day with a dirty black rag she got from wiping out the carbon she noticed in the exhaust pipes. Not greasy from oil burn, but black & sooty from carbon (rich fuel mixture). She went to the dealer to ask about it and was told this is normal, coming from the fuel we get nowadays. Being pretty new with only 6K miles, I can't swallow that. Being a mech all my life, I would never settle for a black, carboned tailpipe as normal. Anyone else notice this on their rides?
Re: XTS running rich fuel mixture?
My chrome exhaust outlets get a little black. I have had to clean them a couple of times. Doesn't seem to be that excessive. Not anymore than any of the other cars I have owned lately. It's just the edge of the chrome outlet that gets a little dirty. I use Gumout on a rag and wipe them up.