Ok,so I just took a trip from Minnesota to Maryland. My factory Exhaust didn't have a chrome extension on it. i had my local exhaust shop put one on. After 2,500 miles driven my tail pipe is jet black like it was a diesel. I have a 2007 LT 2.2l with 155,000. I change oil when i should. I don't know about the pervious owner. Question is.... would this be normal for age and milage. Thanks

 

Welcome to the site, very normal, check the hose the goes between the valve cover and the rubber elbow at the throttle body. By your description it's going to have oil in it, sucked into the Throttle Body



Here a link to a solution I posted awhile ago, seems to work.

https://www.chevyhhr.net/forums/2-2l...ormance-58332/

 

Is the coolant under the pressure cap disappearing?

 

Black soot on your tailpipe and especially if it is also on your bumper above the tail pipe can also be caused by running too rich.

 

thank you for your replys

 

It's probably caused by the Direct Injection. All vehicle manufactures that employ DI have the same result. If this is not the source,,,,,,see all the above.

 

It's a 2.2, so no DI