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James Hart · 02-02-2013, 11:28 AM

HC ppm is raw, unfired fuel, CO% is rich mixture running out of oxygen before fuel is completely burned... how are the plugs, wires, cap, rotor, coil, etc? It has to be missing to have HC that high.

You could try raising your idle a bit to see if that helps.

I'm going through the similar here in Ocean County NJ on my 93 K1500 Blazer (still looking to score a 67-72 Chevy at some point). I just bought it, tried a couple things and still failed (4 trips so far). I'm just going to replace EVERYTHING spark & emissions wise before heading back next weekend. It's got 172k on it and no real service records for the last 50k+ (original owner wrote novels of records for the first 110k+ of it's life)

02-02-2013, 11:28 AM	#12
James Hart Registered User Join Date: Sep 2012 Location: tr.nj.us Posts: 52	Re: Truck failed emissions HC ppm is raw, unfired fuel, CO% is rich mixture running out of oxygen before fuel is completely burned... how are the plugs, wires, cap, rotor, coil, etc? It has to be missing to have HC that high. You could try raising your idle a bit to see if that helps. I'm going through the similar here in Ocean County NJ on my 93 K1500 Blazer (still looking to score a 67-72 Chevy at some point). I just bought it, tried a couple things and still failed (4 trips so far). I'm just going to replace EVERYTHING spark & emissions wise before heading back next weekend. It's got 172k on it and no real service records for the last 50k+ (original owner wrote novels of records for the first 110k+ of it's life)