What is your question?
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What is your question?
Idles fast , high Rpms when driving ,bad gas mileage ,when driving slowly accelerates to 25 30 mph at 1500 Rpms or so. Truck is a 2000 model. V6 (Only had option for. 99 )
How long has your 1999 GMC C1500 had this problem?
Long time
A professional scan test is the first step to a successful diagnosis. Cleaning throttle body is pointless! IF that were the issue - you could force idle speed to drop by manually turning throttle linkage to the idle stop screw. ▪️ Vacuum leak ▪️