driving home one night last week my 08 jk began shuddering at speed. shudder became worse at acceleration but still had power. upon coming to a stop it abrutly died. i had to double pedal it at stops to keep it going. took it to a local shop and what they found was that the catalytic converter was causing to much back pressure causing it to misfire. this is covered under my federal emissions warranty so it was sent to the local dealer. they have had my jeep for almost a week now and still have not diagnosed the problem. has anyone else had issues like this? is it common? and if so why would the dealership be dragging their feet on this? if a local shop can figure it out why cant they? are they just trying to find a problem to make me pay or is it really something more complicated than that?

 

Catalytic converts do not commit suicide, they are murdered. What I mean by that is, for the most part when calatytic converters go bad, it is a result of some other problem ( EG: an engine misfire that allows raw fuel into the exhaust, overheating the converter causing it to meltdown) The dealership may be trying to figure out what the underlying problem is.

 

so got an update from the shop. they replaced the spark plugs, pcm, removed cat to see how would perfom. acted better but went right back to running rough. been one week and they still dont know whats wrong with this thing. thank god everything is covered under the 8 and 80

 

talked to the dealership today. theyve had it for two weeks now. they "think" its a spring in the number two cylinder. this comes after they replaced the spark plugs, pcm and catlytic converter. getting way pissed.

 

See if they'll replace the fuel filter under warranty too. Couldn't hurt, even though when they go bad they usually cause severe bucking at speed.

 

Call me crazy...and I know we don't have a MAF sensor, but that sounds just like a bad MAF.

Do you have an automatic Trans?

 

yes i do have an automatic trans

 

Just a thought.....could it be a locked up converter? Anyone?

 

ok I read this thread then went to dinner while waiting for others to arrive i was waiting in the jeep idleing and what do you know my 2010 Standard transmission JK ( 3500 miles) starts a Shuddering of its own it did it twice within a matter of 20 mins. it never died but im now paranoid and leave for Pennsylvania in two days somebody please give an idea of what this could be

 

Anybody? I would hate to think i have a loose spring in my engine with so little miles. Has anyone experienced this so early on? Did it clear up or did you find an answer?