1992 3.0 hc (ppm) way too high

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08-10-2012, 01:20 PM

Evan Mansfield

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1992 3.0 hc (ppm) way too high

1992 ext cab 4x4 3.0

hc (ppm) idle limit is 400
truck is running at 1459

passed cruise but idle is way too high

any ideas?

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08-10-2012, 02:42 PM

Dirt Driver

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What were all the other readings? What state are you in? Do you have a cat converter? Is the truck stock? Need more info.

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08-10-2012, 04:12 PM

scope103

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You're idling way too rich. Run the check procedure (from the diagnostic connector) of the O2 sensor. If it works at speed but not at idle, you could have a problem in the heater circuit (though that should throw a code). You could have an exhaust leak (air mixed in exhaust makes it look lean to O2 sensor, ECM incorrectly moves rich).

The other readings would be helpful. http://www.autoshop101.com/ / Technical Articles / Emission analysis