Re: 03 WJ 4.7 with 192,000 miles - replace catalytic converters?
If it has 192,000 miles on that motor i would personally change it. Magnaflow makes a decent universal one that is cheaper than most. You can also find stock type ones for around $200. Or you can run it without the cat but it will be a lot louder and you will have a check engine light on.
2010 Brilliant Black SRT8: Corsa Cat-back, AFE Stage 2 CAI powder coated black, Toon by Johan, Black powder coated intake, Black powder coated strut bar with red SRT, Red BT Catch Can, Stainless Braided Lines, Red HEMI half covers, Full LED Interior, Carbon Fiber wrapped trim, Carbon fiber badges by Nate, Carbon fiber license plate frame, Custom "SMKDYOU" plate, Black reps, and more to come......