How to lower High HC GPM Emissions?

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JoeyT

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Hi, I have a '96 ram 1500 5.9L v8. Took it in for emissions, and it failed due to High HC GPM. I put in a new air filter, cleaned the throttle body, cleaned the MAP sensor, cleaned the IAC sensor, and the Throttle Position sensor. Seafoamed the engine by aspirating most of a can through the brake line and put the rest in the gas tank. Finally, put in new Champion spark plugs gapped to 0.044" and filled up with shell 85 octane unleaded. Took it back for emissions, failed again. This time, the hc gpm was a little lower, but still too high. What else can I do?
 
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JoeyT

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Also put in a new PCV valve.
 

dodge dude94

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Only thing I can think of is to put a new cat and O2 sensors in it
 
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JoeyT

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Just replaced the 02 sensors about a year ago... could they have gone bad that fast?
 

dapepper9

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Run your tank down to 2/3 full of your normal gas. Film the rest with e85 if you can find any in your area. The alcohol fuel burns cleaner and with a slightly different chemical emissions mix and the extra chemicals usually aren't tested for
 

dodge dude94

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Have you checked your plenum? You might be burning oil which would explain the high HC.
 
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JoeyT

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I have not checked the plenum. I hadn't even heard of it before subscribing to this forum. Is it pretty difficult/involved? Is it super costly?
 

dodge dude94

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I have not checked the plenum. I hadn't even heard of it before subscribing to this forum. Is it pretty difficult/involved? Is it super costly?

Checking involves removing the throttle body, shining a light down into the intake, and using a mirror to look around. If you see pooled oil in the corners, it's blown the gasket out.

Replacement consists of removing all the accessories and removing the intake manifold. Then you take the plate off and replace the gasket.
 
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JoeyT

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Checking involves removing the throttle body, shining a light down into the intake, and using a mirror to look around. If you see pooled oil in the corners, it's blown the gasket out.

Replacement consists of removing all the accessories and removing the intake manifold. Then you take the plate off and replace the gasket.

Hmm. I'll have to look into that. Might be the reason I've been burning so much oil. About 1-2 quarts per month.

Also, we seafoamed the engine by aspirating it through the brake line. Should I put more in the gas tank?
 
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JoeyT

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Is this the right kit?

http://www.rockauto.com/en/moreinfo.php?pk=2194496&cc=1095702&jsn=469
 

dodge dude94

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Hmm. I'll have to look into that. Might be the reason I've been burning so much oil. About 1-2 quarts per month.

Also, we seafoamed the engine by aspirating it through the brake line. Should I put more in the gas tank?
Yeah, 1-2 qt per month is a bit high. You won't see the smoke, just see it disappearing. lol
I guess you could dump a bottle in on 1/4 tank of gas and run it near empty, but I don't think it will fix your issue.
I personally would buy only Fel-Pro gaskets. They're thicker, made better and more accurately.
 
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JoeyT

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Ok, got the Fel-Pro plenum gasket ordered, but now my alternator is going out. Any suggestions on which one I should get from rock auto?
 
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