Effects of gutted catalytic in TJ - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 02-28-2002, 03:22 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Effects of gutted catalytic in TJ

I have a '97 4 banger TJ. A couple weeks ago the catalytic converter clogged up and I was broke, so I cut it off with a saw-zall, hollowed it out and clamped it back on. Now the 'check engine' light is on. How is this affecting the computer? Is it alright to leave it like this or do I need to replace the cat?

Sponsored Links
Advertisement
 
post #2 of (permalink) Old 02-28-2002, 05:14 PM
 
Join Date: Aug 2001
Posts: 596
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Effects of gutted catalytic in TJ

Yeah you should replace the cat. what may be happening is since the cat is open the senors are getting differnt readings. if your loops back in to the intake then your emssions are alot higher and the engine is wondering why.

http://www.csupomona.edu/~sdmiller1/jeep.htm
surveyboy is offline  
post #3 of (permalink) Old 02-28-2002, 06:01 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: Effects of gutted catalytic in TJ

What is happening is where you have hollowed it out your 02 sensors are sending the wrong readings to the pcm. This will cause your Jeep to run a very lean fuel mixture. You need to replace the cat before you kill your 02's as well. Hope this helps.

Bowlsie

Sponsored Links
Advertisement
 
post #4 of (permalink) Old 02-28-2002, 06:36 PM
Can't Get Enough
 
Join Date: Sep 1999
Location: Cotopaxi, Colorado
Posts: 1,036
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Effects of gutted catalytic in TJ

Youir '97 TJ is ODB11 compliant. Which means you have 2 O2 sensors. One upstream, ahead of the cat, and one downstream, behind the cat. The upstream O2 is used primeraly for fuel trims, and the downstream O2 is used for performance testing the cat. Your pcm can recognise that your catalyst is inop. This is why the check ingine light is on. Catalyst performance. The only way to turn off the light is to replace the cat and clear the codes. As far as damage to the system, it can wear out your check engine light for being on all the time. It shouldn't hurt your O2 sensors at all, just the anoying light.

FYI, The O2 sensor is way down the bottom of the food chain as far as mixtures are concerned. They are used for fuel trims to correct long term adaptives, then multiplied by load, coolant temp, throttle position, etc.



dorfs is offline  
post #5 of (permalink) Old 02-28-2002, 08:19 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: Effects of gutted catalytic in TJ

If you continually run a vehicle with bad 02 sensors on a OBD2 vehicle it can destroy a cat. The pcm uses the o2 sensors signal to constantly fine tune the fuel mixture so the cat can do what it is intended to do and that is clean the exhaust. So in all reality the 02 is not on the lower part of the food chain. I have seen it many times on numerous vehicles. If the sensor fails to perform it will cause the feedback control system to go into open loop mode with a rich (fixed) fuel mixture. This will cause emissions to rise and the convertor can very well be damaged because it will overheat.

Bowlsie

Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome