CAT's and CODES

CATS: I am running my original cat and am wondering if it may need replacing- how can I tell- it passes emmissions ok. Also, can someone recommend a good aftermarket cat, to maybe increase performance? I have the 4.0HO, '91. I read on some earlier post about the connections not being easy and I dont want to deal with any of that- anything that just plugs in?

CODES: I have been using the ingnition-key trick to test the computer codes using the flashing check engine light-got a couple- but don't have the list of code meanings... anyone feel like posting it or telling me where I can get it?

Thanks much...

Check This Out

Hey Dude, this is accurate for 4.0 L HO's up to the OBD-II (1996 first year)...... Anyway, Good Luck !!!! Bill-93XJ

Link to Zilla website for codes --->