Contentious high idle when started until I shut it off

The cruise control will not engage until the vehicle reaches a predetermined speed so it will not have any effect on idle speed. I would inspect the intake hoses and vacuum lines to ensure that everything is connected and clamps are tight, also nothing interfering with the throttle cable. The next thing to check is for any trouble codes in the power-train control module. The last thing to check will only be possible with a scan tool that can view sensor parameters, specifically the TP_MODE, SHRTFT1, SHRTFT2, LFT1, LFT2. The throttle position mode pid should read closed at idle and PT for part throttle and WOT for wide open throttle, I've replaced many throttle position sensors for the same thing and they showed PT when the engine was at idle with the throttle plate closed.