Anyone cut there catalytic converter off?

Travis · 04-07-2002, 12:56 PM

I am having some engine trouble and I have fixed everything I can think of. I am now thinking maybe it's the cat is clogged up. Has anyone ever had a motor problem where cutting the cat off helped? Please describe.
Mine runs almost like one of the wires is off the plug. Like I'm only hitting on 5 plugs. (89 4.0 cherokee) It has new cap, rotor, plugs, wires, computer, air filter and pcv valve. Exhaust is my last guess.

johny1i · 04-07-2002, 02:10 PM

One more thing you may check is your fuel filter, although I am not familiar with the 4.0 (I have the 4.2). To answer your question (and you better not work for the Feds <img border="0" title="" alt="[Wink]" src="wink.gif" /> ), yes my catalytic converter is removed. On 258 Jeeps, there are no sensors, etc. on the catalytic converter--the last sensor is the oxygen sensor on the exhaust manifold. However, you will have to make sure that your computer is not taking any readings from your cat (like another oxygen sensor, etc.) that would confuse the computer if it is missing. Also, if your converter has a return tube that brings exhaust back to the engine, make sure it doesn't have a sensor on it--if it just routes the exhaust back into the intake or something then you should be ok. Another alternative is to take the cat off, knock out the screens on the two ends, bust up the inside, and gut it out. Some guys have suggested this because it will get you through a visual inspection.

mozz · 04-07-2002, 03:18 PM

It can be a number of things.Was the motor running rich or with a miss for a while.(one reason for a cat to clog)Can you pull one ign. wire off at a time to narrow down to which cylinder is missing.If all the wires seem to pull down the RPM's when you pull them off it may be a fuel filter or something electrical.
I have seen a shorted distributor or a shorted coil act the same way.
Good luck

4wheeler4CJ · 04-08-2002, 09:01 AM

(I don't mean to "walk" on your post, Travis) <img border="0" title="" alt="[Wink]" src="wink.gif" />

Hey, Mozz, sounds like a sweet setup you got there. My '77 in my signature below is still in the works, but I'm very eager to get it going. How do you like it with the 360? I'll be running 33x12.50's, I don't want to get into regearing, plus it'll be used on the road more often than off (we have somewhat limited off-roading around here.)

Travis · 04-08-2002, 01:23 PM

No problem 4wheeler.

I have a new fuel filter on. Forgot to mention it. It has never ran right since I owned it. I bought it from an auction and my guess is that it has been under water. We had to replace the carpet due to the smell. When the carpet was up the inside of the jeep was full of water.
It was running off only 5 cylinders for a while. The computer went out and it was not spraying gas out of one of the injectors. Think maybe that's my problem?

4wheeler4CJ · 04-08-2002, 04:23 PM

Travis,

If it's been underwater, anything could be the problem almost (unfortunately). "Storm" damaged cars can be real pains in the A**es. However, the symptoms you described could most definitely be enough to cause your problems.

No gas out of one of the injectors will cause the problem you're describing. Let us know how you make out. <img border="0" title="" alt="[Wink]" src="wink.gif" />

Mudweiser · 04-08-2002, 07:27 PM

I would say make some other checks before cuting off the converter. I alredy asume that you checked to see if yo have spark the next i would say is conect a fuel pressure gauge to make sure that you have the specified fuel presure. then check to see if you have power going to each of the injecters you can do that by ataching a noid light or a test light. if the vehicle had been in a flood it is most likley an electical problem or it could be coroded conections. i know for gm there is a tool that you can atach to the injecters to, turn the fuel pump on, and manualy pulse the injecters. i hope this helps

Larry Daniels · 04-08-2002, 09:43 PM

What catalytic converter?