bad Cat & misfire-which comes first

[jfmalinowski]

bad Cat & misfire-which comes first?

[PortugalFocus]

Misfire first then it will cause your cat to get clogged with excessive un-burned fuel.

Though a clogged cat will cause your car to run poorly and have possible mis-fire related symptoms. The best way to check is unbolt the cat and see if it runs just as poorly.

What are you experiencing?

[jfmalinowski]

CEL was on and getting hesitation when accelerating. Changed wires and re-gaped the plugs. Plugs were very clean and dry. Still getting hesitation. The CEL has gone on and off again but now it's on all the time with a hesitation.

[73sport]

As stated, when the CAT has to burn a bunch of RAW fuel because the engine passed it through w/out burning it, the cat runs hotter and can plug.

From what I've seen these things can run pretty bad for a LONG time before the CEL gets lit. Couple that with running bad gas for exteded times and the CAT takes a serious beating.

Sounds like you have ignition issues (no sparky to the plug) and it likely played a role in the cats failure.

A plugged cat won;t allow the car to make any power. It may idle fine, but won;t accellerate if being choked by a restricted exhaust. Both items need fixed. Try unscrewing the rear O2 sensor and see if it revs up better.


Edit: sounds like you need new coils!
Watch is run in the dark and/or spray the coils with a fine mist of water and see if it makes it run worse. You can also grab the coils with you hand while running. If its bad, you'll know it. < not advised, but it works! lol