I’m hoping someone may be able to help with this one. I have a 2006 Wrangler Rubicon. Original owner. It’s got 164k miles on it. 4.0 inline 6 with standard tranny(natch). Yesterday morning, I was driving to work and the Jeep started to chug badly. Was at highway speed at the time. Could only speed up to 55 for the remainder of the drive without the engine chugging. Got the Jeep home and had the codes read. Codes were cylinders 1 and 4 misfire, random misfire, and warm up catalyst efficiency below threshold (bank 1). All sounded like my coil pack was going bad. Replaced it. Not throwing those codes anymore, but Jeep won’t get above 35mph and won’t go above 2k rpm. Previous to this, I thought I got into some bad gas, due to some random missing. Also had a flashing engine light, which I found was a warning about the catalytic converter. Any ideas or recommendations? I’m headed to a repair shop tomorrow to have a diagnostic run if I don’t get any more ideas. I’m considering replacing the fuel filter? Any help would be greatly appreciated!
Poor performance and misfires
- Thread starter Radioflyer1105
- Start date
Could be that your catalytic converter has started to clog up. Mine suddenly clogged so badly that my top speed went from 70 mph to 5 mph in a quarter-mile on the highway while coming home from a wheeling trip. Mine clogged because one of the two mini-cats upstream of the main cat spilled its innards out which blew downstream into the main cat which nearly completely clogged it.
A muffler shop can pressure test the cat to see if the cat is starting to plug up. You could also have a bad upstream O2 sensor. If the chugging/reduced power happens when the engine is cold right after starting it and for the first half-mile or so I would rule out the O2 sensors.
A muffler shop can pressure test the cat to see if the cat is starting to plug up. You could also have a bad upstream O2 sensor. If the chugging/reduced power happens when the engine is cold right after starting it and for the first half-mile or so I would rule out the O2 sensors.
Jerry,
Thanks for the reply! My Jeep is running like this whether it’s cold or warmed up. Is there anything that can unclog a cat if it’s just carbon build up? I’m assuming carbon since it’s in the exhaust system. I’m not really looking forward to having to replace the cats, since it’s a single pipe from the exhaust manifold. I will see if the shop can do a pressure check on the cat tomorrow.
There's nothing you can do to the cat to clean it. Once they get clogged that's it, they need to be replaced. Ignore the internet myths that they can be cleaned and restored to operation.