Pontiac Repair: Sunfire Missing, fuel pressure guage, air flow sensor

Question
I have a 1996 Pontiac Sunfire 2.2 It started to have a slight miss. The check engine light came on coded for a lean cylinder. I was told it could be the fuel filter so I changed that. It didn't help. The car then totally quit on my wife after having it towed 42miles home when it was dropped from the wrecker it started right up (still missing though only worse now). The check engine light was back on. It coded for Throtle position sensor. Replaced it no luck. Then replaced EGR, IAC, Air flow sensor and no Luck. This time when I started the car the power for the entire car would go on and off in rythem about the speed of the blinkers. On then off then on then off it kept running but barley. My wife said that was what it did to her before it quit. I shut it off and it started right back up just with a miss again. Then cleaned all ground connections no luck car is still missing and stranded me luckly right by my house. Car would not start up. A few hours latter it started right up again. still missing. I have a 2.2 S-10 work truck of the same year. I have been swaping parts of the same part # to see if anything works but haven't found anything yet. If you have any suggestions that would be great.

Answer
Hi Charles:
I would put a fuel pressure guage on this at the filter you will need a few adapotor to make it work but My guess is your low on fuel pressure and that is the cause of the misfire and the lean code. The pump may have quit altogether. and the ride on the tow truck jared the pump enoug hto make it start working again. On these car the pump will cut out and just a sharp rap on the bottom of the gas tank with a rubber mallet will jar them enough to make them start to run again. You could have issues with a power feed to ground to the pump as well.