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West TX GT
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I seem to recall someone posting they had a failure of their green cats. It was quite a while ago. I think the general consensus is if boosted go catless or stay with the stock cats. The green cats last longer but still give in to the heat eventually. Since aftermarket cats still fail smog tests there is no real reason to run them other than odor control. Since removing the factory cats is already breaking the law, why not run without?
OP
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Bmaughan
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Well I believe my stock cats are failing so I need to replace them. So technically replacing them with another epa certified cat if warranted is technically legal. And it seems that on average green cats don’t throw codes and that’s all they check in Az so that was the reason for the choice. I would’ve loved to go catless but I’m trying to be lawful about it.. haha
I’ve seen the green cat ad that says they’re good to 850hp. I’m running about 700 who so I really hope so!
I’ve seen the green cat ad that says they’re good to 850hp. I’m running about 700 who so I really hope so!
GregO
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HJS cats will survive and most likely get you through emission testing.
https://www.fabspeed.com/hjs-catalytic-converters/
Performance Industries is runner up to HJS in my opinion when comparing Domestically produced cats vs. German made.
Green Cats “GESI” isn’t even on the radar when compared to HJS or Performance Ind.
Performance Ind. cats are more affordable than the HJS option.
sigintel
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Two sets of cats:
1. New unabused used for getting codes set and compliance.
2. Old Stock - possibly cracked and center of cores completely fell out/missing. ALWAYS seem to leave a little bit of shrapnel in muffler. Are they punched out? naaaahhww, must have failed recently...
1. New unabused used for getting codes set and compliance.
2. Old Stock - possibly cracked and center of cores completely fell out/missing. ALWAYS seem to leave a little bit of shrapnel in muffler. Are they punched out? naaaahhww, must have failed recently...
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Roh92cp
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I had Kooks setup I got from a friend who ran them for 2 years and one of the green cats was failing in the center fins started folding on one and the other was showing some signs as well. He was running 740 wheel whipple cal, that was later retuned with HP Tuners for more power and timing.
SheepDog
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I've been running the Kooks Green cats now for over 10,000 miles. 13psi and E85 the entire time. No problems at all. Perhaps corn isn't as hard on the cats as gasoline. The black filth left on my tailpipes from gasoline, compared to the relative absence of deposits when running alcohol may be some indication of this.
Roh92cp
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My bet is if you could take your cats off and look at them the fins in the middle would be folding in to some degree.
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Roh92cp
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This is what mine looked like.
SheepDog
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That sucks, or blows depending on how you look at it. So I guess that is happening simply from the volume or flow of exhaust pressure hitting them? Kooks rep told me they were good to 900hp, though not sure if he meant Wheel or Crank.
Roh92cp
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Yeah likely 900 crank, and the cat protection built into the calibration has a lot to do with how long they last also.
SheepDog
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Good to know. since I'm Emission exempt until 2024, I'm gonna order the cat delete pipes and put the cats on the shelf until emissions day. If I keep the car that long anyway
Dominant1
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Boost vs cats boost wins and if you don't remove them bad cats-->. Bad cats vs engine, Bad cats win by blowing your motor...
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