91 chevy caprice failed emissions
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91 chevy caprice failed emissions
someone help me out please. my caprice with a 5.0 305 motor failed its emission renewal. wires plugs and air filter seem to be good. the tech . that tested me said i BARELY failed because of unburned hydrocarbons[gas]. should i replace the oxygen sensor? smog pump? any help would be great
#2
Originally Posted by BiggWaukegan
someone help me out please. my caprice with a 5.0 305 motor failed its emission renewal. wires plugs and air filter seem to be good. the tech . that tested me said i BARELY failed because of unburned hydrocarbons[gas]. should i replace the oxygen sensor? smog pump? any help would be great
Change Fuel & Air Filter, Change Spark Plugs,PCV Valve, Switch to a higher octane gasoline and go from there, no reason to believe smog pump or oxygen sensors yet, by the way I'm assuming your computer is not throwing any codes right ?
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our442
Originally Posted by BiggWaukegan
someone help me out please. my caprice with a 5.0 305 motor failed its emission renewal. wires plugs and air filter seem to be good. the tech . that tested me said i BARELY failed because of unburned hydrocarbons[gas]. should i replace the oxygen sensor? smog pump? any help would be great
#5
No engine light/code, hydrocabon reading high= engine temp low(cold), give it a good run on highway speed then come back and retest it, don't let it run at idle for too long prior to do the test.
Last edited by New guy; 02-11-06 at 03:56 AM.
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if you havent had an oil change done recently you can probably lower the hc a little just by changing the oil.
might check vacum lines and repair any damaged vacum lines as a vacum leak can cause hc to be high also.
might check vacum lines and repair any damaged vacum lines as a vacum leak can cause hc to be high also.
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Try a couple of small bottles of gasline antifreeze (alcohol) in the tank with some fresh gas, and make sure you give it a good highway run prior to test, to heat up catalytic converter to optimum temperature. If your that close, this should get a pass next time