Quote:
Originally Posted by carlsontheflyer
The EPA rule book says that primary cats must be present. The secondary cats are too far downstream to heat up enough to initiate the proper chemical reaction. In other words, they are not enough to burn off the remaining HC, CO and NOx gases. The vehicles that only have one cat or dual cats downstream rely heavily on the EGR system, which in those cases is much more prone to failure as it gets clogged up with carbon buildup.
Of course, many, if not most emission inspectors are ignorant of the fact that some cars have primary and secondary cats, or what cats looks like, for that matter. They will often glance under your car with the aid of a mirror on a broomhandle, see the resonators and assume those are the cats, and you get a pass. 
Next time come to my station for emission test. I wont open your hood. 
I'm in Alpharetta / Johns Creek area. |
Cool, I live off of Nesbit Ferry. Moving soon though. I think the key is the knowledge part of this. Most inspectors don't even know all the tricks to get around what the computer reads, let alone what stock parts come with the car, so if the computer says 'pass', they just roll with it.