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Rear cat delete/modification

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Old Jul 15, 2015 | 07:30 PM
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02_Black_On_White's Avatar
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Default Rear cat delete/modification

hey guys i've been thinking about this for about a year now and I cant decide what I should do so if anyone has any suggestions or any personal experience to offer that would be great. I want to delete my rear cats all together without throwing a Mil(Check engine) light. Ive narrowed it down to two real possibilties my first being order flowmaster high flow cats for $100 each and have my local shop weld them, my problem with is I really wanted to get a good change in sound and im afraid that the high flow cats wont give me what im looking for, my other option which I can do myself would be to cut the cats out put in a piece of 2.5" pipe with 02 bungs and run MIL eliminators, is this something people do? will it affect my engine, I feel like MIl eliminators are hit or miss when it comes to throwing codes.

Besides the pipe, I would use some nice stainless steel exhaust clamps linked here
http://www.latemodelrestoration.com/...FVMXHwodZnUGLw

and my only real option for the 02 bungs would be these

http://www.summitracing.com/parts/pf...FUWPHwodP6sJUg

as far as mil eliminators this is something I was looking at

http://www.rpmoutlet.com/mil-eliminator.htm

appreciate all the input!

EDIT: I am not worried about the inspection, ive got that covered !

Last edited by 02_Black_On_White; Jul 15, 2015 at 07:33 PM.
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Old Jul 15, 2015 | 09:33 PM
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I cut all four of my cats off and added the o2 sensor mod with no cel. The mod I'm referring to is adding the spark plug non-foulers to lift the rear O2 sensors out of the flow of the exhaust. Not much of a sound difference IMO.
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Old Jul 16, 2015 | 12:00 AM
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Default Rear cat delete/modification

I removed all four of mine. I am also straight piped and the exhaust dumps at the y pipe temporarily until I can have an exhaust run. The difference in sound with and without cats was pretty noticeable. Maybe some top end performance but who knows it might just sound faster. Removing two cats didn't do a whole lot. If you want a sound difference you're gonna want to modify all four and do the Gotts O2 sensor mod like stated above. My CEL comes and goes. I haven't done the O2 mod yet which I will get around to once I get headers.

No cats is definitely fun. Flew by my buddy in second gear and lifted the throttle at 5k-ish rpm's and he told me he saw a small blue flame. I now have videos to prove it
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Old Jul 16, 2015 | 12:57 AM
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Just buy a programmer. You can turn the rear oxygen sensors off.
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Old Jul 16, 2015 | 10:36 AM
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Default Rear cat delete/modification

Originally Posted by Carcrazygts2
Just buy a programmer. You can turn the rear oxygen sensors off.
I have a superchip cortex I don't know if I can do it with mine. You think I can?
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Old Jul 16, 2015 | 10:36 AM
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Default Rear cat delete/modification

Originally Posted by jstockert
I cut all four of my cats off and added the o2 sensor mod with no cel. The mod I'm referring to is adding the spark plug non-foulers to lift the rear O2 sensors out of the flow of the exhaust. Not much of a sound difference IMO.
Yeah thanks I've been looking at that.
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Old Jul 16, 2015 | 12:38 PM
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Default Rear cat delete/modification

Will these work for mil eliminators ? It says works on 99-04 lightening


http://www.latemodelrestoration.com/...sor-Simulators
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