No power and running rough. New cat. Help! -
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Go Back > Models > Jeep Wrangler Forums > TJ Wrangler Technical Forum > No power and running rough. New cat. Help!

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Unread 09-13-2010, 05:22 PM   #1
Registered User
1997 TJ Wrangler 
Join Date: Oct 2008
Location: Austin, TX
Posts: 90
No power and running rough. New cat. Help!

I have a 1997 4.0L TJ that is running really rough.

Here's the run-down.

A couple of weeks ago I heard a rattling around the transfer-case. My MPH went to crap, like 97 miles to the tank! I also smelled exhaust while I was driving and eventually couldn't get the Jeep past 35 MPH.

After jumping on the forum, I determined it was the catalytic converter. I just sold my welder about a month ago, so it was obvious I was going to have to take it in.

I called some muffler shops and they wanted anywhere from $600-$800 to replace the cat. Finally, I limped it to JeepMasters in Austin, TX and they replaced the cat for about $220.

I drove it out of the shop this morning and have the SAME problem! It doesn't rattle anymore (obviously) but the symptoms still exist. I was able to run it for about 15 minutes before it started giving me problems. Once again, I pulled in to the driveway with a rough engine and a Jeep that wouldn't go past 40MPH. What the heck is this? Is it the O2 sensor(s)? Which one? The check engine light is NOT on... This is my daily driver - please help!


yoshi280zx is offline   Reply With Quote Quick reply to this message
Unread 09-13-2010, 05:38 PM   #2
Registered User
1999 TJ Wrangler 
Join Date: Mar 2010
Location: mass
Posts: 72
I'd have it scanned anyways to see if there are codes. Could be any of a number of things.
jeepinjohn72 is offline   Reply With Quote Quick reply to this message

catalytic converter , o2 sensor , poor gas mileage , power loss , rough idle

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