1993 4.2L the passenger side catalytic converter "i think that's what it is" gets glowing red and the exhaust seems like it get excessively hot within a mile or two of driving. Then it starts to back fire and the check engine light will come on after about 2-3 miles of driving. The overheat light or radiator light doesn't come on. When you stop and let it idle the RPM's go down and up it back fires a little and tries to stay running but then it will die. (It does the same thing if you let it just idle for awhile). It will start right back up. . Could it be the O2 sensor because I notice it will blow a fuse sometimes under the seat that has something to do with the O2 sensor.

 

The catalytic converter is clogged.

 

How do you unclog it?

 

With a plunger of course! lol

Sorry, my bad. Its not clogged. The engine is not burning off all its fuel. The excess fuel makes it way into the converter and burns in there, causing it to glow red. Defective O2 sensors can cause this problem, but usually it is related to improper ignition. Could be fouled plugs and wires and maybe even a bad ignition coil pack.

 

I'm glad I don't have to use my new plunger I have relatives coming to town that eat to much fiber. Thanks