Failed Emissions today...doh

[GN84Turbo]

Well, here are the specs:

HC (PPM)

max Measured

15 mph 126 96
25 mph 101 75

CO (%)

max Measured

15 mph 0.79 0.62
25 mph 0.59 0.36

NO (PPM)

max Measured

15 mph 1118 1827 (DOH!)
25 mph 978 1387


SO...what should i be looking for? I stupily leaned out the mixture because i had just installed my hotwire yesterday, which may be cause of the high NO, but I thought I'd double check. Possibly the EGR valve or I need a new cat? Any advice would be most helpful. I only get 1 more chance.

TIA,

 

[turbowrenchhead]

Excessive combustion temps cause high Nox. I would look at your EGR.

 

[cool 84]

A lean mixture or a malfunctioning EGR valve will make the NOx too high. Only problem is if you richen it then the HC will go up. A catalytic convertor isn't real efficient at reducing NOx but I'm sure it wouldn't hurt. I always get a pretest just in case so it doesn't go into the state's computer. It's an extra $20 but it's worth it if it saves you from being classified as a gross polluter. It's saved me before.

I got lucky and I knew the smog guy from highschool. I failed because it was running lean and I asked him if I had a way to adjust the mixture if I could try it again. He smiled and walked away while I turned the FP up and came back when I was done.