running without cats...any problems? backpressure and codes?
Thread Starter
Joined: Mar 2003
Posts: 8,319
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From: North Carolina
running without cats...any problems? backpressure and codes? ok i was gonna do headers but then i read about the problems with codes, between that and the price i decided to go with the full length ypipe that tbyrne has. im gonna run that with some sims. should i see any problems in the o2 numbers like this? like anything that the headers are doing? also any problems with lost back pressure? i was told since the headers changed the o2 location and the temp was cooler inside it messed it up. and taking out the cats would that change it either? between that and the backpressure im just worried. let me know guys, thanks
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Re: running without cats...any problems? backpressure and codes? anyone? anyone else try this kind of set up? will it make my comp think it was lean and run it richer or what?
Re: running without cats...any problems? backpressure and codes? HEaders wont cause any problems on their own.....but the fact that you will not have rear o2's means that you will need simms to fake out the computer...the coeds it throws will be telling you that the catalytic is working correctly...doesnt hurt any performance.
try reading this thread for the rest of the jargin
https://ls1tech.com/threads/showflat...rue#Post654305
try reading this thread for the rest of the jargin
https://ls1tech.com/threads/showflat...rue#Post654305
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Re: running without cats...any problems? backpressure and codes? well someone told me that it will throw codes with sims. that the first o2's will actually read leaner. or would thsi actually make numbers more true? without the cats holding back the crap would it let the exhaust flow freer giving it better numbers?
Re: running without cats...any problems? backpressure and codes? you will lean out a little with headers.....and the simms are for the 2nd o2's.....you gotta get tuned so that you get best air/fuel cause it will be leaner due to no backpressure holding things back a little....your engine will gulp more air with no backpressure...making it run lean.... so go get tuning to fix it....
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Re: running without cats...any problems? backpressure and codes? well see im not gonna run headers, just the pipes that bolt up to the stock manifolds that delete the cats. is this still the same
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Thread Starter
Joined: Mar 2003
Posts: 8,319
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From: North Carolina
Re: running without cats...any problems? backpressure and codes? ok so what numbers should i monitor to have a new tune made. i am using the predator. just let me know what i would need to do to take care of this properly, thanks so much!
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Re: running without cats...any problems? backpressure and codes?
i was also told after going catless it was hard to go back? is this true?
If you gut your cats, obviously you cannot put the catalyst back in. Best way would be to make a "test pipe" with the appropriate flanges that would bolt in the place of your cats. This way you can put the cats back in whenever you want.
Thread Starter
Joined: Mar 2003
Posts: 8,319
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From: North Carolina
Re: running without cats...any problems? backpressure and codes? yeah i want to get the pipes that replace the cats so i still have the cats. so i would beable to go to running the car without cats to running with cats without any problems right?
TECH Apprentice
Joined: Nov 2001
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Re: running without cats...any problems? backpressure and codes? you will want sims if you dont run cats. I have cats on my setup and I still run O/2 sims. Have too cause there are no rear O2 bungs on the Y pipe.
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Re: running without cats...any problems? backpressure and codes? let me rephrase that i wanna get some pipes that bolt in place of the stock piece taht is where the cat is now. so this way i can put the cats away if i needed them later, but would be runnign stock manifolds, from there to the collecto 2.5" pipe and then the stock collector to a flowmaster
TECH Enthusiast
Joined: Jan 2002
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Re: running without cats...any problems? backpressure and codes? dude, if you r not doing headers, then don't waste your money please
get an electrical cutout and be happy with it = performance and sound wise
seriously!
get an electrical cutout and be happy with it = performance and sound wise
seriously!
Re: running without cats...any problems? backpressure and codes? I'll sell ya my gutted cats....I gotta take them off my car when I put on my headers at the end of this month.... send me a private message if you're interested.
TECH Fanatic
Joined: Jun 2003
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From: Further South than Hell
Re: running without cats...any problems? backpressure and codes? I run shorties and O/R custom pipes to replace the cats at the track with sims. Since the sensor locations have not been altered, no problems. I made that decision to facilitate staying legit for sniff patrols. Of course I'm sacrificing about 15rwhp VS LT's (27 rwhp gain for my setup)but I will compensate with 125 dry NOS shot. All together I run mid 12's in summer and With NOS and cooler weather/lower humidity I should be guetting in mid to low 11's.
Before you do headers check NC sniff laws and base ur decision on that, this should make ur life easier at inspection time
Before you do headers check NC sniff laws and base ur decision on that, this should make ur life easier at inspection time
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Re: running without cats...any problems? backpressure and codes? yeah i do state inspections and its all visual and obd2 based, i dont plan on working there much longer so i need something to replace come inspection time so i can pass if i cant get anyone to pass it for me
