Cats
#11
Basically my point in all this was that over time cats become ineffective, and the emissions standards that are out there are really based on being able to pass a vehicle after the cats are mostly not doing anything as long as the rest of the vehicle is in good condition/maintenance. CATs are very effective in reducing pollution during the 1st 7 years and then you can watch the emissions creep up year after year if you're in a place that actually measures emissions. Stories I've heard first hand of people who have had to replace CATs to meet emissions actually tends to be somewhere around 15 years, but other things that are easier & cheaper to to do, to get a pass, start at around 10 years.
#15
I'm just saying... I've seen the tailpipe emissions readings of a well tuned car without any cats, and a well maintained 10 year old vehicle with stock cats. The car with cats did not have the cleaner emissions. Also, there is a reason that the warranty on the cats, while longer than the powertrain warranty, ends before the 8th year.
About 20 years ago, Hot Rod magazine did a story about a engine they build for I think was a camaro. They were in Cali so they tried to get it passed for emissions. No shop would touch it because it had no cats and they refused to pass it. Something about being afraid the government would come after them and take their license away. They finally tested it unofficially and it passed with flying colors.