Is there something wrong with my truck

[The almighty schmuck]

Its a 2011 gmc sierra crew cab 4x4 z71 all terrain with the 5.3 heres the symtoms

1-i put an exhaust tip on that was black it burned the paint off and rusted so i removed it wire wheeled it and painted black again with bbq pit paint within a week the paint has burned off again

2-when in park or netural and you rev the engine it takes a while for the rpms to drop back to idle what i mean by a while is 5 to 6 seconds instead of 1 to 3 like you would expect

3-truck seems to be lacking power. I havnt driven others of the same set up so i cant be sure but my 07 tundra was way faster so was my 06 f250 and my 99 youkon

4-i regularly tow my 7500 lbs camper and it will not tow it in 5th gear at 60 or 65mph it always is in 4th and turning higher rpms than id like for extended runs and only getting 6mpg

Any input would be appreciated

[Dnt]

You might want to sneak a peek at your catalytic converter after the truck has been running for a while, if it is cherry red then yes you have a problem. Should have some engine codes if the catalytic convertor has stopped up!

[O_J_Simpson]

You are describing a normal GM truck of your vintage.

[The almighty schmuck]

No codes ive never seen a gas engines exhaust get that hot at the tip

[Colossus]

plugged up cat would be my guess, but someone already guessed it.

[CoffeyLover]

You might want to sneak a peek at your catalytic converter after the truck has been running for a while, if it is cherry red then yes you have a problem. Should have some engine codes if the catalytic convertor has stopped up!

 

 

plugged up cat would be my guess, but someone already guessed it.

 

 

No question about it, clogged cat! I can't think of anything else that would cause your symptoms.

[GhostWriter]

Hard to believe all this could be happening without the CEL on.

 

Also, as written, it almost seems the problem started after the tip was added to the exhaust.

 

Other thing, is you should be able to "smell" this, which wasn't mentioned.

 

Most important question would be "when" all this started.