Hotter spark plugs?

[91legacyawdturbo]

So on my ss I'm still trying to get the ej20g to pass emisions, Ive been able to drop the legacy pinks in to it the g's rails , now I'm failing my co and nox I'm thinking about putting in a hotter plug, I was able to cross an ngk plug to a autolite step hot plug. I'm hoping the hotter plug will burn off the unburnt fuel better and I hope my cat isn't bad, any ideas on how to get the nox down the limits are 2.5 and I'm at 3.6 the co are at 1.75 and the limits are at 1.5 thanks Brian.

[Legacy777]

NOx is a high heat and CO is a low heat combustion byproduct. If you are high on both, you've got a problem somewhere with the engine, and/or the cat is not working.

This diagram shows what I mean. (click for larger image)

[93forestpearl]

I like the hand-written note at the bottom, lol.

[Legacy777]

Hahaha.....yeah I took that note

[evolutionmovement]

Yeah, you don't have an unburnt fuel problem. Sounds like cat to me. Your CO should be turned into CO2 and the NOx into N2 and O2

[91legacyawdturbo]

Well it turned out my cat was bad.