Just wondering if anyone that lives in a state that has emissions checking stations or just likes to be "legal" has replaced 1 or both of the catalytic convertors with a high flow aftermarket version. Most of the aftermarket cats that I've seen are rated for specific engine displacements and vehicle curb weights. Example "up to 7.5L engines with vehicle curb weight of 7,000 lbs. or less" Does this mean if the cat is will allow the truck to pass the sniffer test as long as the displacement is less than 7.5 liters?

My thought would be to replace both cats with one high flow version that would still be legal, because I'm not a big fan of paying up to a $2500 fine if I'm caught without a cat....