California Emissions and Catalytic Converters

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swathdiver

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For the GMT900 platform, is there any differences between the engines and cats between Federal and California emissions other than CARB numbers on certain parts?

I was reminded that my truck has California emissions (NE1 and NU5) and wondered if there is a physical difference between the cats and y-pipe and if it has anything additional that a Federal vehicle does not.

TIA!
 

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I know when I was buying cats for my GMT800 there were Cali legal ones and the non Cali ones. Some would be listed as " not fir California emissions".
 

GotExhaust.com

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In general California emissions are stricter. Often you will see the Cats have a bigger cell count to filter the exhaust better, ECU could have a slightly different tune, EGR differences, etc...basically its usually choked down more and emits a cleaner exhaust.
 
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swathdiver

swathdiver

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In general California emissions are stricter. Often you will see the Cats have a bigger cell count to filter the exhaust better, ECU could have a slightly different tune, EGR differences, etc...basically its usually choked down more and emits a cleaner exhaust.

Thank you Chris, I've been searching without success for more specific information. I put Federal cats on my truck completely forgetting that it came with California emissions and wondered what exactly the differences are.
 

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