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I see alot of questions / comments about true dual exhausts. I am a little confused? I have been told by muffler shops that it it against federal law to convert to dual exhaust. All the shops I have talked to say you can put on headers and a cat-back but that is it. If there is a way around this, I would love to know. I would like to let my 95 bird and 2002 F-150 breathe. How do you get around the single O2 sensor issue?

Thanks for any insite.
 

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Yes, it is illegal to remove a working cat, even if you are going to replace it with another cat. You either have to end up paying "Cash up front, no receipt" or buying the ART kit and doing it yourself. For the removal of the second set of O2 sensors you need to get "MIL Eliminators" which you can get from just about any mustang performance place, or you can get a chip that turns off codes from those two sensors.
 

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Do you know where I can go to get a total package? Or any web sites with the information?

Thanks.
 

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No------it's not illegal to convert our cars to "true duals". To keep it legal you'd have to add yet one more cat converter so then you'd still have exhaust flowing through 2 cats a piece. In all you'd have to have 4 catalytic converters under the car....Don't 'stangs have somethin' like 6 of 'em.?.....it's all about the cats
 

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Eric420 said:
No------it's not illegal to convert our cars to "true duals". To keep it legal you'd have to add yet one more cat converter so then you'd still have exhaust flowing through 2 cats a piece

Sorry it is Illegal and against federal law to modify any emission related part!!! You can how ever replace it with a CARB exempt replacement part! that is federal law! Some states you can get by with modifying the exhaust but it is still illegal to do it!
this applies to street driven cars not off road driven vehicles
 

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Aren't the 3 cats on a regular Mark (single pipe) the same as the ones on the 4.6 Birds? If so couldn't you use the 3rd cat from a Mark VIII LSC which has 2 inlets & 2 outlets on a T-Bird? I'ts all Ford stuff. From an emissions standpoint wouldn't it perform the same?
 

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You either pay $900 and do the install yourself or find a shop in your area that will do it no questions asked. Some people here have had local shops do it for as little as $300. I found a shop in my area that will put duals on and will be getting them soon. I haven't had a chance to get a price yet, been to busy.
 

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Under Federal law you are not allowed to move or tamper with any emissions related part. Sometimes you can replace an emissions related part with an aftermarket part if it has proven itself to not hurt the emissions function. California even allows entire drivelines from the same vehicle class and newer to be transferred into an existing car. i.e. you can take the DOHC engine from the same year or later and swap it wholesale over into your t-bird. At that point emissions laws apply to your car on basis of the Lincoln you swapped from.

So in summary you can swap in a 96 Lincoln driveline into your 94 cougar, (i am dreaming here) and run whatever exhaust is legal on those cars. However you cant take and put true duals into your existing car, legally of course. If if you were to add extra cats that would make the car cleaner, it is still illegal. Dont you love how a beaucracy works?
 

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It really comes down to if you want to stick to the letter of the law or not. If you're in the Republic of California, you don't have much of a choice.

If you are in the great state of Florida (as far as I know we don't have inspections anywhere but possibly Miami), it isn't a big deal. Yes it is a federal law and thus applicable in any state, but there aren't inspections and shops will do anything here.

Your choice.
 

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It is NOT illegal to modify the exhaust as long as you still have cats and mufflers. Maybe in California or other extremely liberal states. I have custom dual exhaust on my '89 Caprice. I have gone through emissions and the shop that installed it did not mention any legal complications.
 

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hey on your 2002 f 150, what engine do you have? I have a 99 ext cab 4x4 5.4l, and I had a shop run true duals for around $400. They just ran pipes off of the cats, back to two mufflers, and out the rear. They won't touch my t-bird, but said that was ok on the f150. good luck
 

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Just because Jim Bob didn't mention it doesn't make it legal.

Here's the facts.

http://www.epa.gov/oar/oaq_caa.html

Sec. 203. (a) The following acts and the causing thereof are
prohibited-

(3)(A) for any person to remove or render inoperative any device or element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this title prior to its sale and delivery to the ultimate purchaser, or for any person knowingly to remove or render inoperative any such device or element of design after such sale and delivery to the ultimate purchaser;


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 federal tampering prohibition pertains to "motor vehicles," which are defined by section 216(2) of the Act as "any self-propelled vehicle designed for transporting persons or property on a street or highway. A light-duty vehicle manufacturer certifies en engine-chassis configuration as meeting the applicable emissions standards for motor vehicles manufactured in a given model year, and it is not legal for anyone to "de-certify" a motor vehicle for "off-road" use.

The general rule is that a motor vehicle emission control system (which includes the exhaust configuration) may not be changed from an EPA certified configuration without subjecting the repair shop to liability for violating the federal tampering prohibition. The exhaust system configuration, including the location of the converters, and exhaust pipe diameter and length, are items specified by the manufacturers because engines and some of the associated emissions systems are generally affected by the exhaust system back pressure, which subsequently affects vehicle emissions. The installation of a dual exhaust system with two converters would, therefore, be considered tampering. The Agency will not, however, require a repair shop to restore a vehicle which has a non-stock dual exhaust system to a single exhaust configuration. A shop may, therefore, replace sections of pipes on such a system, except for that portion of the pipes where the original catalytic converter would have been located. It would not be considered tampering to install a dual exhaust system with two converters if the vehicle manufacturer certified an identical engine chassis configuration for the vehicle model year or newer that includes such an exhaust configuration.
 

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So is it legal then for us to have a shop remove the mufflers on our cars and weld in those sweet 3 inch tips and remove the resonator and just weld a pipe in? In the not so distant future i'm looking to have this done and i don't want people at the exhaust shop thinkin' i'm nuts for even asking....anyone that has had this done....what did it cost you? I know people say "just go cut them suckers off and clamp some tips on" but after looking at things i don't think it'll be that easy....and welding them on is best anyway....
 
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