Hi I have a 2005 Saturn Vue 2.2 4 cylinder stander, front wheel drive my engine light is on steadly and nothing through the middle we had a electical tune up, ignition coil w contro done drove about two miles and light came back on took back got the catalytic converter replaced light came back on took it back and put another catalytic converter on and light came back on after a couple of hours then took to a different mechanic and put a new battery in drove for about a week came back on and now it stalls at a inopportune time while driving I was wonder if you could tell me what could be the problem or what I should try next. Thank you