Can someone help me please.my car runs perfect starts rite up and drives smooth.but after i stop at a few places and shut the car off.i will turn the key and it kicks like its going to start but then it dont and then when i turn the key and hit the gas a little bit it will start up and stay running.it starts doing that when i shut it off.so i decided to put car md in and it poped the code P0412.and it tells me what to check but i dont know what this means pcm or the air solnoid.i dont know were they are located at in my 2000 buick lesabre.can someone help me please give me a tip on what to check? please? thank you