Could this lady’s problem be the catalytic converter? My own 89 Toyota pickup recently had analogous symptoms! First came the trouble light, which had several previous false positives. Then came the rattling sound. Then came a succession of bad smells. Then came bucking during acceleration. Then came very rough performance. (Tomorrow the shop!) It’s a long shot, but could this jeep have a deteriorating catalytic converter? Good luck to her!
I would imagine that the catalytic converter is the problem. Your car has all of the symptoms. Watch out, however, when you go and get it worked on at the mechanics. Many times they will tell you that the muffler needs to be replaced as well. Most of the time it doesn’t. My recomendation is if it is the catalytic converter, just get that fixed. If the problem persists after that, then replace the muffler. Don’t pay to have something replaced that works.
By “trouble light” do you mean check engine light? Do you have a code from the ECU? It could very well be the cat converter, but you need to make sure before spending $.
Those are the symptoms of a bad catalytic converter; but, a poor state of tune could have hastened its demise. That same lack of tune can cause the replacement to fail prematurely.
I think I had this at Hello during the show yesterday:
A broken motor mount causes the “KurClunk!” when it downshifts. The mount may have broken because it’s a Jeep and the owner mentioned actually driving on rough roads occasionally – or maybe it’s broken just because it’s a jeep! But to be fair, my Honda CRV also had a similar KurClunk which I thought would be trans, but turned out to be motor mount. Take the broken mount plus KurClunk, and eventually the exhaust gets a crack between the manifold and catalyic converter. She’s slow enf in the parking lot that she smells the sulfer. How bout them apples? I hope she isn’t also getting CO inside the car at all speeds.