Title says it. The ring is on the tip of the exhaust, and before recently the ring wasnt there. what could cause this?

 

Did you just put on a new exhaust tip?

 

it's most likely carbon build-up from running rich

could be an O2 sensor going

 

Its the original tip

the 02 sensor is new. got all new sensors when the engine was rebuilt....ive read that clogged injectors could cause this...??

 

A pic would be worth 1K words.....r u talking on the outside????....they're all black on the inside.

 

Normal, don't worry about it.

 

Like this?

 

Like this.

 

Huh. Mine doesn't have it. Anyway, it's never a bad idea to check that tiny, brittle little tube to the MAP sensor.

 

Mine has the same ring but i guess i never thought about it being a problem...

 

mine has always been clean till oh say the last week when I noticed an exhaust leak and see that my catalytic converter is rattling and leaking exhaust at the joint with the muffler. That area also has black residue.

 

Ill check mine for that.