2007 Saturn Ion both check e.gine lights

Computer code says accelerator sensor. Replaced that. Thought it was t throttle body replaced that. Lights are still coming on and runns sluggish with bothlights are on what could it be now the computer or another sensor. When you first take off from a red light or stop sign it will barely move you cant push the petal and get out you have to make sure no one is coming. My husband says it will go off when. It heats up. But sometimes it is after I have went a couple of miles