Isnt the cat for nox, hydrocarbons, and co????
Isnt that why they call it a 3 way cat.
i am a litle confunsed. as I understand co and hydro go hand in hand. if one goes up so does the other.
Now my nox reading is a litle high too.

Should I through a cat in and hope for a pass??, my timing is good 12 degrees BDTC at +- 900 rpm. is,t that the specs???