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Check Codes

Discussion in 'Chevy C/K Truck Forum' started by Coupe302, Nov 10, 2009.

  1. Coupe302

    Coupe302 New Member

    Did a code scan today after I warm up the truck (1990 1500 4.3L V6 TBI),Got code 12, 33, and 42.
    Code 33-map sensor signal out of range, high
    Code 42-electronic spark timing (EST) circuit grounded

    are these code related to each other? The truck is idling high had to retard the timing to lower it but now it loss power.

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