Ditch the dual cats?
06-25-2011, 01:26 AM
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Car: 89 GTA
Engine: 5.7 TPI L98
Transmission: 700R4 w/ Stage 2 shift kit & stall
Ditch the dual cats?
I've got an 89 GTA with the dual cat exhaust and I was thinking of removing them both to add some noise and free up some airflow. Would doing this affect how my motor runs and will it throw a check engine light? I've got a flowmaster muffler but plan on removing that and running two glasspacks near the rear. I also have the stock exhaust manifolds.
06-25-2011, 09:50 AM
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Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: Ditch the dual cats?
Please dont hack up the stock parts! PM me if you wana sell it !
06-26-2011, 08:02 AM
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Car: 1987 formula
Engine: 305 tpi
Transmission: t5
Axle/Gears: 3.45
Re: Ditch the dual cats?
coming from the guy with a ford 9" in the rear. haha
but i am taking out the exhaust in mine right after the manifolds and running it down the sides of my car with a 28" glasspack. it wont run rough without the cat cause there is only one o2 sensor and that is in the manifold/headers you can do what ever you what with it after that, or atleast for the tpi its that way if the gta isnt tpi plz state what it is.
but i am taking out the exhaust in mine right after the manifolds and running it down the sides of my car with a 28" glasspack. it wont run rough without the cat cause there is only one o2 sensor and that is in the manifold/headers you can do what ever you what with it after that, or atleast for the tpi its that way if the gta isnt tpi plz state what it is.
Last edited by 87hellbird; 06-26-2011 at 08:06 AM. Reason: motor
06-26-2011, 10:30 AM
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Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Ditch the dual cats?
Change out your muffler first and then decide what to do with the cat.
When I had a Flowmaster American Thunder and no cat, the car was actually quieter than it is now with the GMMG and a cat....So effectively, the cat has become my muffler.
With glass packs, the cat should take some of the choppiness out of the sound.
When I had a Flowmaster American Thunder and no cat, the car was actually quieter than it is now with the GMMG and a cat....So effectively, the cat has become my muffler.
With glass packs, the cat should take some of the choppiness out of the sound.
06-29-2011, 12:09 PM
#6
Re: Ditch the dual cats?
Just remember, the catalytic converters are an emissions control device, and as such it is against FEDERAL law to remove them on a street vehicle in the United States. Even if your state or local area does not do emissions checks, its still illegal to remove them.
It has to be said to keep thirdgen.org from getting into trouble.
By the way, my car is making 377 horsepower to the wheels, and I still have the cats and all emissions devices hooked up and working.
It has to be said to keep thirdgen.org from getting into trouble.
By the way, my car is making 377 horsepower to the wheels, and I still have the cats and all emissions devices hooked up and working.
06-29-2011, 12:16 PM
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Car: 1989 IROC-Z. Original owner
Engine: LB9. Dual Cats. Big Cam
Transmission: World Class T-5
Axle/Gears: BW 3.45
Re: Ditch the dual cats?
If TTOP350 doesn't want your dual cat set up, I've got dibs.
Where are you located?
Where are you located?
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06-29-2011, 08:27 PM
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Car: 89 GTA
Engine: 5.7 TPI L98
Transmission: 700R4 w/ Stage 2 shift kit & stall
Re: Ditch the dual cats?
Located in Roselle, Illinois. I was mistaken though. It's only a single cat. Nearly brand new though.
06-30-2011, 02:29 AM
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Car: 89 GTA
Engine: 5.7 TPI L98
Transmission: 700R4 w/ Stage 2 shift kit & stall
Re: Ditch the dual cats?
Not kidding! I'm in Roselle. Yea, it's a black 89 GTA. Pretty original looking.
When all is said and done I'll have a flowmaster muffler, believe it's a 40 series, and one cat. It looks to be smaller than OEM so my guess is it's high flow. The PO said they just had it put on a few months before I bought the car and it looks very new. Anyone Interested?
When all is said and done I'll have a flowmaster muffler, believe it's a 40 series, and one cat. It looks to be smaller than OEM so my guess is it's high flow. The PO said they just had it put on a few months before I bought the car and it looks very new. Anyone Interested?
06-30-2011, 08:16 AM
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Car: 1989 IROC-Z. Original owner
Engine: LB9. Dual Cats. Big Cam
Transmission: World Class T-5
Axle/Gears: BW 3.45
Re: Ditch the dual cats?
I'm pretty sure I saw your car on Bryn Mawr and Roselle rd yesterday.
06-30-2011, 12:29 PM
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07-02-2011, 12:49 AM
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Car: 89 GTA
Engine: 5.7 TPI L98
Transmission: 700R4 w/ Stage 2 shift kit & stall
Re: Ditch the dual cats?
I was at the Downers Grove cruise night tonight. That one is HUGE! Only saw two third gens though. I've only taken my GTA to the Roselle one once. I'll probably take it this Friday.
07-02-2011, 08:29 AM
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