Why is idle speed changed when replacing tps?

Old tps regulates idle to 750 rpm but new one doesnt. The car idles at 2500 rpm if I remove tps. When I install new tps rpm stays ay 2500. I do have check engine light code 41 and throttle opener was cancelled at some point. I cant reach idle speed screw but I dont want to mess with it unless I know tps is not supposed to change idle speed.