Kooks Headers With OEM or GREEN Cats?

CowmaroV8 · 03-26-2021, 05:40 PM

Hello friends,

I have narrowed down my research to going with Kooks headers for my build and have hit the final road block of going with the option of OEM Catted connections or for ~$600 more going for their GREEN catted connectors.

Is the price difference worth it in the long run and what are the main differences to sway in one direction or another?

Background on my build and plans to help:
2016 2SS Auto Daily Driven
Lethal Garage E85 kit
Pray ported IM and TB
Roto-Fab Dry CAI
Factory NPP Exhaust

Will be adding Granatelli Wires, new spark plugs, spark plug heat sleeves and coating the headers prior to install.

Future plans for the car are to remain N/A and in the very distant future go with a full heads and cam package on the car. Emissions testing every two years checked by way of OBD-II (this will be a race car used on the track only.)

Thanks,

cmitchell17 · 03-26-2021, 05:54 PM

I have the green cats and the reason I got them was I hate the smell. So far the seem to do ok, not nearly as good as the stock setup at reducing fumes. You will get a smell at cold start and they will take longer to warm up, once warm I haven't been able to confirm I smell the unburnt hydrocarbon smell.

That being said, I have not been able to get my kooks and cats to not leak, I have had to resort to that crusty cheap muffler repair paste that hardens and that still didn't seal it up completely.

I also regret them just because the sound quality is so bad, there is a lot more unrefined exhaust noise that comes into the cab and listening to the car from the outside you can hear a lot of noise radiating from the collector area, especially ticking noise. I am highly considering going back to the stock manifolds and cats, if it wasn't for the increase in airmass I got from them compared to the stock setup. I am not typical of you're average Camaro owner however and I am highly sensitive to noises and nvh.

I can't comment on the regular cats just because I've never ran them.

CowmaroV8 · 03-26-2021, 06:09 PM

Quote:

Originally Posted by cmitchell17

I have the green cats and the reason I got them was I hate the smell. So far the seem to do ok, not nearly as good as the stock setup at reducing fumes. You will get a smell at cold start and they will take longer to warm up, once warm I haven't been able to confirm I smell the unburnt hydrocarbon smell.

That being said, I have not been able to get my kooks and cats to not leak, I have had to resort to that crusty cheap muffler repair paste that hardens and that still didn't seal it up completely.

I also regret them just because the sound quality is so bad, there is a lot more unrefined exhaust noise that comes into the cab and listening to the car from the outside you can hear a lot of noise radiating from the collector area, especially ticking noise. I am highly considering going back to the stock manifolds and cats, if it wasn't for the increase in airmass I got from them compared to the stock setup. I am not typical of you're average Camaro owner however and I am highly sensitive to noises and nvh.

I can't comment on the regular cats just because I've never ran them.

Do you think you just had an bad batch of headers and such and that is why they are leaking or what do you suspect to be the issue? And are you on E85 as well or regular 93?

cmitchell17 · 03-26-2021, 10:47 PM

Quote:

Originally Posted by CowmaroV8

Do you think you just had an bad batch of headers and such and that is why they are leaking or what do you suspect to be the issue? And are you on E85 as well or regular 93?

I'm on E85 and haven't even tried regular gas on it yet.

I honestly think everyone has issues with it leaking. Its not bad enough to where you can hear a exhaust leak but its bad enough to set off codes that are very normally set off when there is an exhaust leak present near the O2 sensor as it can suck in outside air between pulses and contaminate the O2 readings.

It seems like the only way to seal an exhaust system is with a flange connection with a flat gasket like the factory seals it. You would think for a $2500 system they could make it not leak. But it is kind of understandable as they want to make a kit you can bolt on and not need a welder.

If anyone knows some good flanges to buy and weld on let me know haha

03-26-2021, 05:40 PM	#1
CowmaroV8 Drives: 2016 Chevrolet Camaro 2SS Join Date: Jun 2020 Location: Illinois Posts: 27	Kooks Headers With OEM or GREEN Cats? Hello friends, I have narrowed down my research to going with Kooks headers for my build and have hit the final road block of going with the option of OEM Catted connections or for ~$600 more going for their GREEN catted connectors. Is the price difference worth it in the long run and what are the main differences to sway in one direction or another? Background on my build and plans to help: 2016 2SS Auto Daily Driven Lethal Garage E85 kit Pray ported IM and TB Roto-Fab Dry CAI Factory NPP Exhaust Will be adding Granatelli Wires, new spark plugs, spark plug heat sleeves and coating the headers prior to install. Future plans for the car are to remain N/A and in the very distant future go with a full heads and cam package on the car. Emissions testing every two years checked by way of OBD-II (this will be a race car used on the track only.) Thanks,

03-26-2021, 05:54 PM	#2
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,204	I have the green cats and the reason I got them was I hate the smell. So far the seem to do ok, not nearly as good as the stock setup at reducing fumes. You will get a smell at cold start and they will take longer to warm up, once warm I haven't been able to confirm I smell the unburnt hydrocarbon smell. That being said, I have not been able to get my kooks and cats to not leak, I have had to resort to that crusty cheap muffler repair paste that hardens and that still didn't seal it up completely. I also regret them just because the sound quality is so bad, there is a lot more unrefined exhaust noise that comes into the cab and listening to the car from the outside you can hear a lot of noise radiating from the collector area, especially ticking noise. I am highly considering going back to the stock manifolds and cats, if it wasn't for the increase in airmass I got from them compared to the stock setup. I am not typical of you're average Camaro owner however and I am highly sensitive to noises and nvh. I can't comment on the regular cats just because I've never ran them.

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