jeep manifold glowing?

[mudd slinger]

1997 tj jeep 4 cyl 5 speed , manifold glowing light red where the pipes come into one o2 sensor is acting up to (running rich) I have tested the cat converter it is ok timing is ok as far as i can tell I have replaced the o2 censor three times the only trouble codes it troughs up is the o2 censor . it has me stumped ??? other than the o2 censor , the thing is running fine as far as cranking idleing and speed it does have a misfire due to the o2 censor acting up when i unplug it it runs with noproblem

 

[lar]

Funny answer. but I would change the plug to a colder plug, just to experiment.

 

[Dj D]

your cat is clogged
take it off and run without one or clean it out

 

[damaged110]

it is running lean not rich. check for vacuum leaks or a cracked manifold