No power in drive

[BassMedic]

I have a 99 e450 ambulance with the 7.3L, long story short it sat for about 3 months and I put new batteries today to get it started back up.

I changed the fuel filter today, oil and filter changed a few months ago. Fuel bowl fills back up after its drained, and looks brand new inside. After about 2 hours of playing with it I finally got it started, it ran really rough and wouldnt idle unless held to the floor and wouldnt throttle up (figure it had some air in the fuel system from sitting and it was cold, no biggie) after it warmed up it idled fine and revs up fine in park. Put it into drive and it doesnt even have enough power to move itself when put to the floor, same in reverse. CEL came on after cranking forever, trying to find someone to come over and scan it since it can't be driven. Any ideas?

Also was curios if anyone knew what the sensor was thats before the air filters? Air temp sensor? I'm making an intake for it since the stock air box is cracked and am unsure of what to do with this sensor or if it can just be left out.

[BassMedic]

Well bought an autoenginuity last week. Scanned it, found only cylinder 7 was working on the passenger bank in the power contribution test so that would explain why I can't move this 5 ton obese thing lol. Going to check the uvch, really hoping thats all this is.