That is what I am scared about- wiring harnass problem - no the check engine light did go on but the check engine light has not been working for a few years - (does not glow during start up).

is there a way to test whether the cat is clogged ? if the engine is running rich only one side of the engine is running rich otherwise both cats would be glowing red- if the cat is glowing red- is it ruined ? the wiring harnass is a disaster to replace so I would like to confirm that prior to ripping the exhaust apart.

I do think that a clogged/collasped cat will glow red- just never had a clogged cat- I just cannot imagine it happening all at once