Q: high idle on startup, 2002 Chevrolet Avalanche

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high idle on startup sometimes dies when put in gear the longer it idles the better it does have changed many parts no change. have changed the ecm throttle position sensor crank position sensor idle air control valve plugs wires and coils still no change

My car has 210006 miles.
My car has an automatic transmission.

Hey there, it looks like you already did a fair amount of work on this. Another thing that you should take a look at is the throttle body. You may have to clean out the throttle body and get the PCM reprogrammed to correct any throttle body choking. If you’d like to have a local expert take a look, a certified technician from YourMechanic can come to your car’s location to inspect the high idle before you follow through with any more repairs.

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