Mitsubishi Forum - Mitsubishi Enthusiast Forums - '02 Lancer Engine Problem! HELP!

Ok, here's a good one for you guys. A couple days ago, was backing out of parking space in my wife's '02 Lancer ES, and the engine died. Started right back up, drove home fine. Now I also notice that if I punch the accelerator from a dead stop, the engine hesitates for a fraction of a second (kind of bogs for a second) and then picks up no problem. Yesterday, while sitting at a stop light, the engine started to bog down and the oil pressure light flickered on a couple times, but went out by itself, and stayed off when driving. This is with the air conditioning on all the time. However, I did try the acceleration trick with the air off, and it doesn't matter- the engine still hesitates for a half a second before taking off. Any thoughts?
Also, I put a bottle of Chevron fuel system treatment in the tank, against my beliefs. This is the wife's car. I've never had a single engine problem with any of the trucks I've ever driven, so I'm lost! Please Help!! Thanks for any help.