i have a 70mm TB from inlinefour.com now when i start the car in the morning, it is pretty good..then i drive it and it idles at like 2k after its warmed up. now if i shut the car off and turn it back on, then it will idle at 1500rpm. theres no vacuum leaks,i have tried adjusting the idle screw. whats wrong? could a bad 02 sensor cause this?? anyone?

 

Bad o2 would cause it to run in open loop. You've posted this before haven't you? I'm thinking about it... Maybe someone else can figure it out.