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Old 08-26-2011, 12:56 AM   #13
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Originally Posted by mnmax View Post
The amount of HC and CO exiting out the exhaust is basically regulated by the EGR either before or within the catalytic converter to be routed back into the engine to be burned. Whatever is left over is supposed to be trapped in the cat. If either of those fail, then the result will be too much emissions exiting the exhaust.
I'm going to have to strongly disagree with you there about what the EGR does. You are partially right about it reciculating exhaust gasses back into the intake, but its purpose is NOT to burn left over HC's and CO...Its only purpose is to reduce NOx by lowering combustion temps when it dillutes the intake charge with inert exhaust gasses.

OP, leaky injector is a definite possibility. Or, like MNMAX said, the CAT is another possible cause. I would lean more towards the injector though since the numbers show that the HC's are way too high, higher than the CAT is supposed to filter out any way.

Also, take a look at the vacuum lines that go to the fuel pressure regulator. If there is a vacuum leak there, the regulator may be leaving too much pressure in the rail at idle.
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