Big Trouble No Solution? 94 VR6 GLX

I bought my Passat (VR6 GLX, AT) a little over a month ago, and it is my first car. A few weeks ago I started having problems, the car would shut off while I was driving!! It would start right back up after I pulled over and started it. So I took it into Firestone to fix the alignment and do a quick look at it. My car had been in a previous accident that didn't show up on CARFAX before I bought it. Everything on the right side of the car (save the body and struts) had to be replace ($1400). I get the car back a few days later and everything's working nicely until a few days later, when it starts to shut off on me again, while I'm on the freeway, and this time it takes me 3-5 minutes to get it started again. So I took it in a few days later as I needed a way to get to school until the weekend. They ran an on-board computer diagnostic, called later and said they couldn't find anything wrong with it and asked for more information, (Asked if it happened while I was accelerating or braking) I told them it has happened only when I am accelerating or letting of the gas, so they checked on some other things after trying to get it to shut off on them, only got to do it once. They said that the Mass Air Flow Sensor was bad and needed to be replaced, I had to order the part ($323.98) which took a week to get. I got it back 2 days ago and now it's worse than ever not only does it shut off on my while im driving but it takes longer and longer to start it back up, (sounds like its trying to start but just can't) and it happened several times at a stop light, so its not only while im accelerationg, I don't know anything about cars so I'm hoping to get some ideas/answers here... Toss your thoughts this way.

It could be the ECM or fuel pump relay or the fuel pump itself. When it dies & won't restart turn the key to on position & listen for the fuel pump to run for a few seconds.

I checked the pump itself and it was fine, so checked the relay out and it needed to be replaced, so i got the part and put it in but it still shuts down on me... :(

Okay I replaced the power relay for the ECM and it's stopped shutting down, but the check engine light came on and now sometimes the RPM's will drop to 1000 and won't exceed 1000 and if i try to push it further it will shut off and not start.... help!?

Okay I replaced the power relay for the ECM and it's stopped shutting down, but the check engine light came on and now sometimes the RPM's will drop to 1000 and won't exceed 1000 and if i try to push it further it will shut off and not start.... help!?

I think it is back to the mass air flow sensor.

I think it is back to the mass air flow sensor.
Replaced the oxygen sensor and it fixed the 1000 rpm problem, but now it's still shutting down on me... :(

Were you ever able to find out what the problem was?