l have an 02 wrangler. Recently the car has run at idle very rough. the sound is all over the place. when u rev it, it has a short sputter and then goes. when u get on it same thing. if ur in 3,4,5 gear and pin it, its got nasty backfiring through my magnaflow exhaust and it sounds like the axle is jumping. it pings really bad. we put computer to it and it is a misfire. is this typically what it should sound like. any other issues?
3 '' inlet

out of curiosity how big of an outlet is ur magnaflow 3''?

Which cylinder is misfiring? The OBD I l should tell u which one it was.
Check all of the spark plugs- looking fro proper gap & any damage or oxidation. If they r worn out change them. If that does not fix the problem then check the wires for damage & wear. Replacing them may be an easy & cheap option (usually 25-30 bucks)

IF this does not help, check the distributor. l think 2002 was the last year that the 4.0L had a distributor (2003+ went distributorless, but l could be wrong) If u need it then a cap should cost u about 50 bucks.

Last option is to go buy a Chilton or Hayes manual (or the factory service manual for extra $$$) & start diagnose ur issues with that.