cat delete
Acct Suspended APR 2026 by request
Joined: Dec 2010
Posts: 10,367
Likes: 1,272
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
yep, taking the sensors out completely and tuning out the codes is the easiest way in my opinion... you can buy o2 simulators that plug in place of the rear o2's and that fools the pcm or you could have the rear sensor bungs lengthened so that when the sensors are put back in they are not directly in the path of the exhaust and should read differently from the fronts to keep the cel off but I don't really like that method especially when there is an easier alternative
Instructor
Joined: Nov 2016
Posts: 244
Likes: 103
From: Pueblo West CO
Unless you're building a pure race car, please don't do this. Modern cats have plenty of flow to allow not only any reasonable power level, but unreasonable levels as well. I'm putting over 700 to the wheels through cats.
Future generations thank you for doing what you can to protect our environment.
Future generations thank you for doing what you can to protect our environment.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Unless you're building a pure race car, please don't do this. Modern cats have plenty of flow to allow not only any reasonable power level, but unreasonable levels as well. I'm putting over 700 to the wheels through cats.
Future generations thank you for doing what you can to protect our environment.
Future generations thank you for doing what you can to protect our environment.
I'm at 450 RWHP (Heads/Cam/FAST90/Headers) and I'm running high flow cats. The power gain without is insignificant.
Instructor
Joined: Jan 2012
Posts: 201
Likes: 6
From: Atlanta Georgia
My car came without them but still throwing errors.
I absolutely disagree that it's easier to have it tuned out, as it's expensive. A couple of spark plug defoulers and a Dremel are all you need to make the codes go away.
That said, why remove them? No real additional power, no better sound, higher chance of fine.
If they weren't stupidly expensive, I would have added them back as soon as I got the car.
I absolutely disagree that it's easier to have it tuned out, as it's expensive. A couple of spark plug defoulers and a Dremel are all you need to make the codes go away.
That said, why remove them? No real additional power, no better sound, higher chance of fine.
If they weren't stupidly expensive, I would have added them back as soon as I got the car.
Le Mans Master
Joined: Sep 2014
Posts: 5,278
Likes: 539
From: Kelowna BC
My car came without them but still throwing errors.
I absolutely disagree that it's easier to have it tuned out, as it's expensive. A couple of spark plug defoulers and a Dremel are all you need to make the codes go away.
That said, why remove them? No real additional power, no better sound, higher chance of fine.
If they weren't stupidly expensive, I would have added them back as soon as I got the car.
I absolutely disagree that it's easier to have it tuned out, as it's expensive. A couple of spark plug defoulers and a Dremel are all you need to make the codes go away.
That said, why remove them? No real additional power, no better sound, higher chance of fine.
If they weren't stupidly expensive, I would have added them back as soon as I got the car.
Adding cats shouldn't be more than $300 or so.
Fines... depends where one lives, no reinforcement here, some places are stringent for sure.
Instructor
Joined: Jan 2012
Posts: 201
Likes: 6
From: Atlanta Georgia
Mail order tune is around $125- $150, not expensive (but you do lose the car for a couple weeks, good winter time thing to do if you have winter).
Adding cats shouldn't be more than $300 or so.
Fines... depends where one lives, no reinforcement here, some places are stringent for sure.
Adding cats shouldn't be more than $300 or so.
Fines... depends where one lives, no reinforcement here, some places are stringent for sure.
So I could pay 50 times what I did for an inferior solution. And the law is federal, so unless you're outside the US...
And no, high-flow cats are not $150 apiece, lol.
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Le Mans Master
Joined: Sep 2014
Posts: 5,278
Likes: 539
From: Kelowna BC
I paid $3 for the spark plug defoulers. Mail order tunes are a waste, as they will NEVER be optimal, or even more optimal than stock, for your vehicle.
So I could pay 50 times what I did for an inferior solution. And the law is federal, so unless you're outside the US...
And no, high-flow cats are not $150 apiece, lol.
So I could pay 50 times what I did for an inferior solution. And the law is federal, so unless you're outside the US...
And no, high-flow cats are not $150 apiece, lol.
