1993 Chevy FullSize van

[Super Scout]

93 Chevy Van, 350 TBI about 70,000 miles. Hopped in it the other day at work and the van had no power, driving it felt like it was pulling a trailer. In neutral you rev it up engine sounds great, no miss, no issues. Replaced fuel filter, O2 sensor, TBI Gasket, and Sparkplugs and wires. As well as Dist cap and coil. Runs a little better but not like it should. Any ideas ? I am thinking its a sensor but I am not sure where to start. Exhaust feels strong, no pingy under load so I dont the the cats are colgged.

[tanz45]

Forward o2 only right? Remove the o2 and drive, any improvement. Good way to rule out a clogged cat (just incase).

Fuel pressure?

[Super Scout]

Fuel pressure was 13 pounds which we were told was ok, removed the O2 sensor ran a lot worse lol.

[tanz45]

Check for weak spark? Any slack in the distributor? Pick up coil? (Hate just throwing money at stuff though) Codes?

[Sloth_Fratelli]

4l60? mine did the same before it crapped the bed. ive got a pump out of a 93 k2500 you can borrow to help diagnose if ya want