Stalling problem

I have been dealing with this problem for sometime now with no luck so if someone could help me figure this out that would be awesome. When my car is cold and I start it up it runs fine but if I drive it on the highway for awhile and then stop and get some gas, when I go to turn it on it starts and stalls and backfires. You can really smell the gas when this happens so it seems to be running rich. The only way I have found to correct the problem is to really stomp on the gas in first gear and sometimes it will correct itself. I have replaced the plugs, wires, cap, rotor, ignition module, MAF, fuel pump, and the distributor with no luck. Last winter it got so bad that no matter when I started it, hot or cold, it would just start and stall and I couldn't get it to correct itself. I ended up replacing the MSD ignition coil I had on it and it seemed to fix the problem. It ran fine for a couple of months and I thought I had it fixed until the problem came back and has been progressively getting worse. The only engine mods I have are a cold air intake, underdrive pullies, and bumbed timing. It seems like something is making my iginition coil go bad but I can't figure it out. Has anyone dealt with a problem like this or should I just bite the bullit and take it somewhere, which I hate to do. Please help.

To answer your questions, I have not checked the fuel pressure regulator so I will have to test that this weekend. When it starts and stalls, if I try to start it again it keeps doing the same thing. When I'm driving and trying to correct it, it will backfire really loud. It almost sounds like a shotgun being fired. I pulled the codes and I forget the exact number of the code but it said it was running rich so that is when I replaced the MAF and the O2 sensors and the codes went away. It did not pull any codes last time I checked it.

Yes I did reset the codes. I was buying some parts at the ford dealership and one of the technitions told me that the code I was getting was probably b/c of the MAF so thats why I replaced it. After that I reset the codes and havn't got another one since. I think I saw a thread from someone with the same problem about a month or two ago but I never saw if they ended up figureing out what was wrong with it.