idle problem

2002 MITSUBISHI GALANT
197,749 MILES • 3.0L • V6 • 2WD • AUTOMATIC
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CALVIN Q MCQUEEN
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The car is barely idling above 500. it is rough doing take off and when sitting at a light. I had it checked for Error Codes (P0102,P0141)I replaced three of the HO2S(1-1,1-2,2-1) also replaced MAF sensor Cleaned throttle body, changed spark plugs and wires and yet the engine is still having idle problem. I even made adjustment with the idle needle just to keep it from stalling out.
Jun 30, 2016 at 5:05 PM
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JACOBANDNICKOLAS
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Have you checked engine compression?
Jun 30, 2016 at 8:22 PM
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CALVIN Q MCQUEEN
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no i have not. car will start as long as i push down on the accelerator. i think my throttle is going bad.
Jul 1, 2016 at 5:19 AM
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CARADIODOC
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Hi guys. I'll stick my nose in here in case JACOBANDNICKOLAS is gone for the holiday.

Was the battery recently disconnected or run dead? This is a real common problem with Chrysler products, and they have a lot in common with Mitsubishis. If memory 12 volts was lost to the Engine Computer, it has to relearn "minimum throttle" before it will know when it has to be in control of idle speed. Until that is done, the engine may not start unless you hold the accelerator pedal down 1/4", you won't get the nice idle flare-up to 1500 rpm at start-up, and it will tend to stall at stop signs.

To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals.
Jul 1, 2016 at 8:56 PM