Catalytic converter Bypass Pipe - Page 2 -
LinkBack Thread Tools
post #16 of 19 Old 06-13-2003, 03:28 AM
Registered User
Join Date: May 2001
Location: Allegan, MI
Posts: 158
no need for a torch, all mighty sawzall

In comission:2004 WJ, stock....

Retired:1994 JGC Laredo I6 4.0L, Smittybilt Outland brush guard, 1 3/4" Daystar coil spacers, custom air intake with tube K&N, Borla cat-back, KC Daylighters 6" 150w stainless steel, Xenon superwhite headlights 85/100w, 235/75/15 Pirelli Scorpian A/T, billit aluminum grill inserts
Kess is offline  
Sponsored Links
post #17 of 19 Old 06-13-2003, 06:39 AM
Registered User
2009 MK Compass 
Join Date: Feb 2003
Location: Gardner, KS
Posts: 162
Forgot to mention. the muffler guys at warpspeed told me that when you put your o2 sensor in it should be the same distance or less to your engine otherwise a cat farther from the engine with an good o2 could also set off an error.
97RedBird is offline  
post #18 of 19 Old 06-13-2003, 09:45 AM
Registered User
Join Date: Dec 2002
Location: Kenmore, WA
Posts: 290
It's my understanding that later model ZJs (like 95 and newer) make use of two Oxygen sensors. One in front of the cat, and one behind. The computer compares the values from each of the sensors to determine if the cat needs replacing. If it does, then your check engine light will come on. Earlier models only use one oxygen sensor, mounted in front of the cat. Replacing the cat with straight pipe on these models will have no effect on the engine, the computer, or the check engine light, since it's downstream of all sensors. If you live in a smog controlled area however, you will fail the emissions test everytime.

1993 ZJ Limited 5.2 - no mods - Red with Gold (what were they thinking) trim.
automan25 is offline  
post #19 of 19 Old 06-13-2003, 03:23 PM
Registered User
Join Date: May 2003
Location: Homestead, Fla.
Posts: 61
Federal law

Don't want to be a wet blanket, AND I'm not a big fan of catalytic converters, but everyone understands that removing or modifying vehicle emission systems is a Federal offense, right? Shops that are caught doing it are subject to a fine of about $125,000 for a first offense. Vehicle owners are subject to similar fines.
There is a reference to this, but I can't put my finger on it now. Owner of a large muffler shop told me about the fines. He said undercover customers have tried to get him to eliminate their 'cats', but he always refuses.

Here's one article.
Exhaust System Repair Guidelines.
The EPA has prepared this fact sheet to answer some of the most commonly asked questions about the types of exhaust work a repair shop can legally perform. If you need any further information about the EPA's tampering policy, please call (202) 564-9240.
Question 1.

Under what conditions or circumstances can a catalytic converter be removed from a vehicle and a converter replacement pipe be installed?
Answer 1.
Under Federal Law, catalytic converters may not be removed and replaced with converter replacement pipes by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing converter replacement pipes on their own vehicles. Anyone who installs such pipes would violate section 203(a)(3)(A) and (B) of the Clean Air Act (Act).
In addition to federal law, forty-five out of the fifty States also have statutes or regulations which prohibit tampering with the pollution control equipment on motor vehicles or driving or selling such vehicles. Thus, vehicle owners who tamper with their own vehicles may be subject to substantial penalties under both Federal and State law.

The only circumstances in which a person would be allowed to remove a converter is if the vehicle is being shipped overseas to an area where unleaded gasoline is not generally available. (Vehicles traveling to Canada or Mexico are not eligible for this exemption.) In this instance the vehicle owner must have a letter from the EPA specifically authorizing the converter removal from the vehicle in question.
pozner is offline  

Quick Reply

Register Now

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

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


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
catalytic converter - test pipe tapenick ZJ Grand Cherokee Forum 1 01-11-2010 08:52 PM
how to tell if catalytic converter is bad rocks00tj WK Grand Cherokee & XK Commander Forum 4 09-25-2008 12:15 AM
Catalytic Converter: Need a New One JoshuaDHarp ZJ Grand Cherokee Forum 11 09-10-2008 06:42 AM
Straight Pipe replacing Catalytic Converter jeff_connors ZJ Grand Cherokee Forum 3 04-06-2008 05:01 PM
replacing the catalytic convertor with stright pipe ? jeepunlimited ZJ Grand Cherokee Forum 4 01-25-2008 06:55 PM

Posting Rules  
You may post new threads
You may 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 Off
Pingbacks are On
Refbacks are On

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