Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Civic VX Federal (original) wont pass CA smog

user removed · 11-09-2011, 09:10 AM

Unburned HC means fuel that has not been completely burned in the combustion process.
Potential sources of incomplete combustion are many.

Fuel injector spray pattern bad.
Ignition signal-spark marginal
EGR system not functioning properly.

Ignitors are common problems.
Clogged EGR passageways also common.

Before you embark on what could be a complicated process, I would try either sea foam or having the injectors cleaned and balanced. Plugged EGT passageways in the intake manifold are common enough to actually be a maintenance process, meaning do them at any mileage over 120-140K even if an issue is not detectable.

Typically when EGR is low you get a high CO reading so the injector clean-balanced flow may be your best first step.

While a fuel filter is good maintenance it will not affect emission readings unless it is really plugged up. Then it would act as a governor, only allowing a certain level of load to be applied to the engine before it would not produce more power.

regards
Mech

11-09-2011, 09:10 AM	#9 (permalink)
user removed Master EcoModder Join Date: Sep 2009 Posts: 5,927 Thanks: 877 Thanked 2,024 Times in 1,304 Posts	Unburned HC means fuel that has not been completely burned in the combustion process. Potential sources of incomplete combustion are many. Fuel injector spray pattern bad. Ignition signal-spark marginal EGR system not functioning properly. Ignitors are common problems. Clogged EGR passageways also common. Before you embark on what could be a complicated process, I would try either sea foam or having the injectors cleaned and balanced. Plugged EGT passageways in the intake manifold are common enough to actually be a maintenance process, meaning do them at any mileage over 120-140K even if an issue is not detectable. Typically when EGR is low you get a high CO reading so the injector clean-balanced flow may be your best first step. While a fuel filter is good maintenance it will not affect emission readings unless it is really plugged up. Then it would act as a governor, only allowing a certain level of load to be applied to the engine before it would not produce more power. regards Mech Last edited by user removed; 11-09-2011 at 09:26 AM..