I'm working on a 02 4.2 with a 1131 lean code and slight missfire. I found the coil was bad and replaced it, still missing. Had it on the lift running and noticed the bank 2 cat was glowing red & thought it was plugged. Changed cat & still misses & turns red hot. could this be leaking isolator bolts causing this?

 

Installed new isolator bolts & gaskets, nochange. Flushed injecters through fuel rail & problem solved.

 

Thanks for the update!

I have been out of town the last several days but before I left I posted a reply. I checked today and see that my post didn't get posted.

I must have bailed out before the reply got sent. Either way, my suggestion was to look strongly for a very lean condition. From my tinkering around with motorcycles I have seen exhaust pipes turn red and in each case it was due to excessive lean condition.

Glad you got it squared away!