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?
