[gdgraph]

I think it's right on the boarder, I've heard from some that the O2 sensors & ECU are so sensitive that just changing from stock to the Kooks high flow cats will result in a CEL. I've also seen a few reports of people installing it and not getting any CEL. I'm personally getting the tune regardless because the A/F ratio and all the engine timing is more optimized, plus I plan to upgrade the intake and port the IM/TB so I'll need it regardless.

Originally Posted by marknagy13

What if I go with the high flow cats then? Because I would really prefer not to tune and void the whole warranty.

[RynoSS]

Originally Posted by marknagy13

What if I go with the high flow cats then? Because I would really prefer not to tune and void the whole warranty.

I've heard that the Kooks Green Cats will not throw a check engine light, as they are emissions friendly. I do have these cats on my C7, but I also had the car tuned with the installation. So, I couldn't tell you if they would've thrown a code or not, but they'd be worth looking into for your situation.

[gdgraph]

Makes sense, the green cats are double the price of the regular ones they have so they better pass.

Originally Posted by RynoSS

I've heard that the Kooks Green Cats will not throw a check engine light, as they are emissions friendly. I do have these cats on my C7, but I also had the car tuned with the installation. So, I couldn't tell you if they would've thrown a code or not, but they'd be worth looking into for your situation.

[JFM-jr]

I spoke to Kooks last week and was told the green cats are more heat resistant. They are for forced induction setups with higher EGT's. No mention of being more CEL friendly what so ever.

[Megahurtz]

Originally Posted by JFM-jr

I spoke to Kooks last week and was told the green cats are more heat resistant. They are for forced induction setups with higher EGT's. No mention of being more CEL friendly what so ever.

The Green Cats are supposed to allow cars to pass emission tests if you have state testing. I imagine a side affect would be the benefits you listed as well. But according to the literature its primary purpose was to pass emissions where other high flow cat options will not.

[marknagy13]

Originally Posted by Megahurtz

The Green Cats are supposed to allow cars to pass emission tests if you have state testing. I imagine a side affect would be the benefits you listed as well. But according to the literature its primary purpose was to pass emissions where other high flow cat options will not.

The green cats wont pass in california either. If you touch the cats at all it will fail the visual inspection. Im more concerned with having the check engine light on. I can switch the headers back in 5 years for smog if I need to.