Chevy & GMC Vans

need some help here. im picking up a 96 or a 98 I forget exactly. the van sat for about 8 months I don't know if it ran fine before it was parked or not. the van starts hard but starts , idles fine when you touch the gas pedal it wants to stall. it was throwing a code for the crank sensor that was replaced and it did not fix the problem but the code has not come back. so far things checked were...

cat -ok
gas - fresh
fuel filter - new
maf - new
egr - removed ,cleaned, worked fine put it back on.
no vaccume leaks
plugs , wire , cap, rotor - new
fuel pressure 54 psi does not leak down over night.
o2 sensor was giving some real goofy numbers have not done anything with it yet im stumped could a o2 cause that problem ? Im starting to lean towards the computer.

Fuel pressure should be 60 to 66 pounds according to repair manual.

yea i know my old van ran fine with 54psi. and either way i should be able to atleast hit the gas and have it not stall with 52psi.

Can you pump the gas and hold it to around 2000rpm without stalling? If the o2 sensor has funky readings why has it not thrown out a code? Or is it throwing out an o2 sensor code?