adding cats

Old Mar 27, 2021 | 05:48 AM
  #1  
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adding cats

Do you guys know if it's easy/accessible to just weld on cats to the downpipes while on the car without dropping the entire subframe and replacing the downpipes? I'm selling my car with catless downpipes and apparently everyone is terrified of the EPA now. Even tried trading it in and dealer wont accept it. I dont have a CEL or anything so I'm thinking even one pair of cats anywhere in the system should satisfy the legality requirements.
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Old Mar 27, 2021 | 07:39 AM
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I cannot help with the technical question, but I want to comment about the EPA part of your thread.

I stay pretty close to the tuning world. Things began really changing in 2018 and the EPA is now becoming more aggressive in the enforcement of tampering with, modifying or removing any emissions devices on cars. One of the main components of the system is any part of the exhaust. Even the second (secondary) CATs on cars were put there BC the manufacturer could not meet emissions requirements and get certified with just one. It's actually a criminal offense to remove, tamper, modify emissions components and the EPA has just been given a set of brand new viscous teeth. In 2019, the EPA started getting aggressive with aftermarket tuners.

https://www.hemmings.com/stories/202...-device-makers

Take a look at what the EPA did to some of these companies and you might recognize one of the names.

I know it's not the question you asked, but the comment you made about the EPA is a good one. Anyone (owners) who makes mods via tuning, exhaust, air intake, EMS data tables mods, should have an exit strategy before they begin. How are you going to reverse the mods you did when you reach the time to sell it? Even selling to a private party, they will not get through emissions testing to get plates in some states already. They'd be in an easy place getting you to buy the car back. Even off road/dedicated track use is not OK by the EPA.

Sorry for the bad news, sorry if I steered the thread off course a bit.
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Old Mar 27, 2021 | 07:57 AM
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It’s highly doubtful that welding primary cats while on the car is going to happen. You need ample room to weld entirely around the pipe
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Old Mar 27, 2021 | 08:43 AM
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Why a pair of secondary cats can not be put back on where they used to go?
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Old Mar 27, 2021 | 10:47 AM
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You can probably weld in a new set of cats onto the mid pipe where thr second cars were. But cats are not cheap, still cheaper than removing downpipe route
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Old Mar 27, 2021 | 04:23 PM
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Yea I did the decat back in 2016 when things weren't such a big deal.

Going to try 300 CEL GESI cats in the bottom/secondary location.

Last edited by kumizi; Mar 27, 2021 at 05:16 PM.
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Old Mar 27, 2021 | 05:41 PM
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Pretty simple job to fit and weld in where secondary cats belong. Just need to order the correct size pipe and smallest overall outside diameter you can find.
any good metal fabricator/ welder could do in a hour or two.
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Old Mar 27, 2021 | 06:29 PM
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Gonna try these

https://www.makperformance.com/GESI-...er_p_2723.html

Just dont know if 2 cats are enough. If new buyer goes to get inspection and it fails, I dunno if it can blow back on me.

Last edited by kumizi; Mar 27, 2021 at 07:15 PM.
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Old Mar 27, 2021 | 06:45 PM
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Originally Posted by kumizi
Gonna try these: https://shop.redline360.com/products...h-output-85030

Just dont know if 2 cats are enough. If new buyer goes to get inspection and it fails, I dunno if it can blow back on me.
What state are you in?

and are you talking a visual inspection? If so just in-line stock cats no?

edit you can’t with SS.
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Old Mar 27, 2021 | 07:05 PM
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depends what state your in.I had to sign a form that I didn't alter exhaust when I traded in my gts in NJ. Going back to stock downpipe would cost thousands to do.
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Old Mar 27, 2021 | 07:23 PM
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Originally Posted by AMG 17GT
What state are you in?
I'm in Texas. I was going to either consign the car or trade it in on a Lambo.

The problem is the two dealers I'm working with say they can get big fines trying to sell a catless car. So I said lets add secondary cats. Now they're trying to figure out if that's enough to cover their behinds.

GESI advertises their cats as EPA compliant.
https://gsportbygesi.com/high-perfor...tems-products/

Last edited by kumizi; Mar 27, 2021 at 07:28 PM.
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