CO was the only thing my car failed emissions on. Shop around here suggested cat and/or ACV valve. He said if both were bad, with Mazda parts it'd cost about a grand. I think for that much I'd just go find a different car.

 

Too much gas not enough air. The carbon monoxide emission is too high...

 

Its about 200 for labor and part to have a cat for a 7 put on at your local uffler shop. About 90 bucks for the cat then labor. ACV's are about 100 used, but could be bypassed. If your nitrogen is real low and your hydro's are too high, then your engines burning too rich. Check your ACV first.

 

I forget my nitrogen (if it was even on there), but the HCs were pretty low. 1/4 of the allowed. The other one (which is something like CO2 compared to amount of CO or something) was really high (high is good on this part of the test). Was over double the min.

Supposedly about a year ago the car had gotten an aftermarket cat. But supposedly they don't last too long.

My parents just need to get their house built so I can register it there where there are no emissions laws