O2 sensor tip is red and so is the inside of the catalytic converter

[wheelman]

The entire inside of the catalytic converter and manifold have a red coating on them. The inside of the cat that has the flex portion has also come apart inside of the catalytic converter. This is on a 17 jeep Patriot. What's got me confused is why is the inside red. The fuel sample looks normal as do the spark plugs. I pulled the cat because it ran like it was clogged up. Runs like crap when you drive it without the cat to. Fuel trims looks good but does have a P219A fuel imbalance and a P0420 cat efficiency code.

 

[paulo57509]

Probably not it, bud you ever have any exhaust work done where someone used red silicone?

 

[wheelman]

Probably not it, bud you ever have any exhaust work done where someone used red silicone?

Nope....it's not my car but one I'm working on. Exhaust hasn't been apart until today as far as I can tell.

 

[kschachn]

Are you using any sort of additive, either in the fuel or the oil?

 

[wheelman]

Are you using any sort of additive, either in the fuel or the oil?

No.

 

[brianl703]

Fuel additives that contain MMT can cause red deposits. No idea what current fuel additives contain MMT, but I know it was used in the past.

 

[tessaseveride]

I'm sure you've already checked this and it's a long shot, but how's the coolant? Those Jeeps use Orange OAT, right? Maybe it could look red when evaporated/concentrated?