removing the Cat, but keeping everything else
I had my exhaust finally installed a few weeks ago. I had a complete cat-back done. 2.5" mandrel bent. I had the 2 secondary cats removed no problem.
Honestly, I can't tell if theres been a performance increase or not and my mileage has been affected only because I've been constantly flooring it to hear the roar
Honestly, I can't tell if theres been a performance increase or not and my mileage has been affected only because I've been constantly flooring it to hear the roar
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Lexus Test Driver
Joined: Feb 2006
Posts: 879
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From: SC
wonderful reasoning you have.
Lead Lap
Joined: Mar 2006
Posts: 560
Likes: 0
From: houston, TX
umm so you have the tools to cut and weld in your garage? good for you. as for me, I'd rather pay someone to do, personally its not worth my time. Just like I pay for cleaning/maid service and lawn service.. same *****...
I'm sure there is an increase, but noone has done any significant testing. However, the best dyno results I've seen for exhausts that retain the secondary cats is about 5 HP, and the best results that I've seen for exhausts that eliminate the secondary cats is about 10 HP. I figure that means that there is probably about 5 HP to be gained by removing the secondary cats.
The problem is that there is a maximum $10,000 federal fine for removing a working catalytic converter. I don't know what the minimum prison sentence is, but that would be MUCH more significant in my book ... especially federal. I guess you just have to figure out how badly you want that 5 HP.
The problem is that there is a maximum $10,000 federal fine for removing a working catalytic converter. I don't know what the minimum prison sentence is, but that would be MUCH more significant in my book ... especially federal. I guess you just have to figure out how badly you want that 5 HP.
CL Community Team
Joined: Apr 2004
Posts: 17,329
Likes: 210
From: Miami, Florida
I'm sure there is an increase, but noone has done any significant testing. However, the best dyno results I've seen for exhausts that retain the secondary cats is about 5 HP, and the best results that I've seen for exhausts that eliminate the secondary cats is about 10 HP. I figure that means that there is probably about 5 HP to be gained by removing the secondary cats.
The problem is that there is a maximum $10,000 federal fine for removing a working catalytic converter. I don't know what the minimum prison sentence is, but that would be MUCH more significant in my book ... especially federal. I guess you just have to figure out how badly you want that 5 HP.
The problem is that there is a maximum $10,000 federal fine for removing a working catalytic converter. I don't know what the minimum prison sentence is, but that would be MUCH more significant in my book ... especially federal. I guess you just have to figure out how badly you want that 5 HP.
Over on solaraguy.org I have seen discussion of 1MZFE Solaras that come in 2 varieties, ones that have precats for CARB, restrictive emissions areas, and others that go under a federal emissions and only have a single cat. This came up when they were talking about use of aftermarket headers that use just a single main cat.
However, I agree going catless entirely is where the big legal issue arises.
Lead Lap
Joined: Mar 2006
Posts: 560
Likes: 0
From: houston, TX
I'm sure there is an increase, but noone has done any significant testing. However, the best dyno results I've seen for exhausts that retain the secondary cats is about 5 HP, and the best results that I've seen for exhausts that eliminate the secondary cats is about 10 HP. I figure that means that there is probably about 5 HP to be gained by removing the secondary cats.
The problem is that there is a maximum $10,000 federal fine for removing a working catalytic converter. I don't know what the minimum prison sentence is, but that would be MUCH more significant in my book ... especially federal. I guess you just have to figure out how badly you want that 5 HP.
The problem is that there is a maximum $10,000 federal fine for removing a working catalytic converter. I don't know what the minimum prison sentence is, but that would be MUCH more significant in my book ... especially federal. I guess you just have to figure out how badly you want that 5 HP.