Mechanics

CHECK ENGINE LIGHT

2004 Chevrolet Epica • 6 cylinder 2WD Automatic • 42,000 miles

My chevy epica will not pass emissions testing due to po171/174 error codes many people have suggested a vacuum leak could be the cause the frame by frame report showed 11.25 hg at the map is this normal
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Promethius
June 12, 2011.




No, that should be up around 16 to 18. It appears to be losing vacuum somewhere.

Wrenchtech
Jun 12, 2011.
I have replaced the pcv valve, ihave tested the vacuum with a gauge and read in the green, ihave also sprayed maf sensor cleaner everywhere with no change in rpm, I did a second scan today and the coolant temp read 107.60f identical to the previous scan and I made sure that the engine got up to temperatureanc the coolant was circulating
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Tiny
Promethius
Jun 12, 2011.
Sounds like you need some professional help.

Wrenchtech
Jun 12, 2011.

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