GM Repair Problems? Ask GM Repair Expert Now.
I am sorry for the long wait and that you are having this problem
99 % of these 2003 Envoy's doing this exact thing are caused by dirty throttle bodys causing the computer to not be able to control the idle correctly
usually a good throttle body cleaning will correct this issue
if by a rare chance it still does this after it being cleaned the only other thing that would correct this issue is reprogramming the computer with updated calibrations to correct that idle issue
but most are corrected with the throttle body cleaning
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