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Old 11-22-2009, 12:24 PM   #1
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Removing cat from exhaust...Good idea?

I live in Mass, where my '88 Suburban no longer has to pass emissions. I need to replace the exhaust and wondered if leaving the cat off with affect it either positively or negatively. Any thoughts from the experts? Thanks.
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Old 11-22-2009, 01:06 PM   #2
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I'm pretty sure removing it is against Federal and State law.

From your own state:

Tampering with any emissions control device or system is hereby prohibited. No person shall take any action that has the effect of causing a motor vehicle to no longer comply with federal law or with the applicable standards and criteria for the motor vehicle emissions inspection and maintenance program or with requirements for motor vehicle registration. Nothing in this section shall be construed to prevent the temporary alteration of equipment for motor vehicle repair or for the quality assurance program established pursuant to subsection (e).

I'm not sure if a muffler shop will even give you an option of not putting a cat back on.

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Old 11-22-2009, 02:51 PM
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A real inspection station will not pass it. I believe it has to be a 80 or older to not run one

Unless of course you know a guy
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Old 11-22-2009, 06:27 PM
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to be safe i would ditch that old prob worn out cat.

then get a nice highflow new name brand replacemnet and instal it.

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Old 11-22-2009, 06:50 PM
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My Blazer came with no cat (PO removed it) and it made it almost unbearable to drive with the windows down.

A new cat is only $112 at Advance Auto. You can get a high-flow one for like $175. Why bother taking it off. I just put the new on one my truck and now I can drive with all the windows down and even the tailgate. SO NICE.
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Old 11-23-2009, 08:58 AM   #6
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Technically it is illegal to remove it based on federal law. Having said that removing it wont hurt anything except your nose. I like driving with the tailgate window open on my truck and you just cant do that without a cat.

I have a 73 jimmy that never had one from the factory and I put on a pair of them. Although, with the new cat laws in the peoples republic of Kalifornia I think it is illegal for me to add them to my truck. According to the letter of the law there is no application specific cat since my truck never had them. I dont care, It is so much nicer to drive the truck with the cats.


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Old 11-23-2009, 09:24 AM
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A good high flow cat does not restrict exhaust flow. I'd keep one on there. Really, no reason to harm the environment unnecessarily, and risk getting caught breaking a federal law.

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Old 11-23-2009, 09:27 AM
Posted in reply to rufusbooth's post starting "Technically it is illegal to remove it..."
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Your truck no longer has to pass a "sniffer test" BUT the inspector is still required to do a visual inspection for safety and emissions. The inspector should be looking under the hood and under the car/truck for the original emissions equipment is not only there but hooked up. Unless you are taking it to one of those stations that check the lights, horn, tires and done, no cat=fail. Besides, as stated above, an aftermarket cat will flow significantly higher than the stock pancake and at that rate will not reduce your engines output and may actually increase it's torque vs. having no cat.

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Old 12-05-2009, 06:25 PM
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Thanks all for your responses. I ordered the high-flow cat and cat back exhaust from J.C. Whitney. Now to get it on the road before the snow flies.
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Old 12-07-2009, 08:37 AM
Posted in reply to GaBnn3's post starting "Thanks all for your responses. I..."
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Mine came factory without one.
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