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Emissions test FAIL--Hydrocarbons Maximus!

J

jokyfo

New member
Looks like I have some kind of air leak. Car idles at nearly twice rpm it should. I believe computer is trying to compensate for the increased air being leaked into the combustion system. Gas mileage has sharply decreased in recent months and there has been a loss of power. "Service Engine Soon" light comes on periodically

Went through emissions last week and my hydrocarbon reading was almost 3 times the limit. Two years ago when I went through emissions that reading was about 1/4 of the limit.

The other two readings, Carbon Monoxide and Oxides of Nitrogen passed although the CO reading was near the limit. Here are the results of the test

HYDROCARBONS-------My vehicle - 2.36 / Standard .80----FAIL
CARBON MONOXIDE----My vehicle -10.62 / Standard 12.00--PASS
OXIDES OF NITROGEN--My vehicle - .61 / Standard 2.00--- PASS

Mechanic friend thinks there may be an air leak through the plenum (upper intake manifold) gasket? Could it be the lower intake manifold gasket?
 


Could be. Could also be a vac. leak. Spray carb cleaner all around the intakes, and at all vac. fittings while the engine is running and see if you find a spot that makes the idle/sound of the motor change. If you find one, then that's the issue.

See if you can scan for codes to find out what the CEL is coming on for. Should point you in the right direction. Even if it's out it should be stored in memory I would think.

Jay
 
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