So I figured it out. Its the throttle butterfly plate thingy. When I push the accelerator it causes the plate to open and when I let off the pedal the butterfly plate isnt closing all the way, which is leaving the throttle open a little. The throttle return spring was filthy but i cleaned it. It still isnt working properly. I tried cleaning the actual butterfly plate but it wasnt really that dirty. It seems like the throttle return spring isnt strong enough to get the throttle plate closed all the way. Ive adjusted my driving so that when Im about to put the truck in neutral I sort of pop the gas pedal and that seems to give the spring enough "springiness" to get the plate closed all the way.Is there any way to increase the tension of te throttle return spring so that it can close the plate without having to pop the pedal?