2009 5.3 Flex Fuel 6sp Sierra with only 4500 miles (all stock)

I washed my truck a few days ago and I noticed the tip was filthy with soot.
I used steel wool to get all the black **** off.

Now two days later the black soot is back all over the outside of the tip.
(pic attached)

Has anyone heard of any know issues/TSB that would cause this on my truck?
Runing rich etc?

My truck also makes sloppy shifts unpredictable sometimes.

Thanks guys

 

Burning an any oil? Maybe a little rich if not but mine did that when it was stock...nothin I'd lose sleep over tho...

 

I'm not burning any oil that I know of.
I'm going to pull a plug out this weekend to see what they are looking like.

I could see if they soot was on there after a few months of driving but not in just 2 days.

 

Trucks run rich from factory. Done to preserve motor. These things are used to tow & generally are workhorses, so GM does that as a safeguard. From what I've been told. Believe what u will. My .02.

 

Could be that you are in a cold climate. There is probably condensation for longer periods of time in your exhaust. That, combined with afterstart enrichment would most likely be your culprit. I don't think you have anything to worry about.

 

Thanks for the replys.

 

It's normal dont worry about. Drive and enjoy.

 

Don't worry about it. Are you one of those guys who let your engine idle all the time when you run into a store?

 

No, reason to shut it off activate auto start keep the a/c nice and cold, arm the alarm run in and run out. Hop in and be on my merry way. They are designed to idle without hurting anything. (short period of time)

 

There's your sooty tail pipe.......