1996 f150 won’t stay running for long

Might be a fuel supply issue. Test to determine if the fuel pressure is adequate.

Sounds like an issue with your alternator/voltage regulator. The next place I would check would be the battery.

scan the codes , might have to pull them off the dash board , the catalytic could be clogged , is there a healthy blast of exhaust when someone guns it ? Did the vehicle sit for a while ?

Yes it sat for a few months. I was thinking the catalytic to but I’ll try them all thanks. And it has two tanks the back one works but the front doesn’t and when it gets hot or pressure builds it pushes gas out of the front tank when I open it up. Any one had that happen ?

so the gas in the front tank has just been sitting ? It might be bad by now ,there shouldn't be any pressure build up it should be vented and if it's somehow pressurized it may be finding it's way into the fuel system causing problems