A&Q about 350Z
Q:
I'll admit that I know nothing about 70's emissions equipment, so that's why I need some opinions. My 1979 Dode Colt failed emissions - it passed every test with flying colors - except for CO% at idle. CO% at speed was well within the boundaries though.
What could it be?
A:
can you post all numbers and engine size?
long story short, high COs normally means you are rich,
A:
It smells rich. But the hydrocarbon readings are low, so I was perplexed. I don't have the numbers with me unfortunately. These cars don't have a catalyst either, so I suppose I'll take a look at the carb and the air injection system and see what's amiss.
A:
My guess is an EGR valve is sticking open at the wrong times, or its spring has failed letting it open too soon.