88 Ranger 2.9 fuel pressure issues??

[Cees Klumper]

Check codes and fingers crossed it's the O2 sensor (or its wiring).

 

[Joey2theG]

Changed the O2 sensor on Sunday. Instant change in warm up time off fast idle. Throttle response was great. It was never this peppy before. Didn’t suffer the issue during my 2 mile test drive. But it did get fully warmed up. Not sure if it’s related, but…
One thing I noticed was that when WOT accelerating from a stop in OD it wouldn’t shift up from first. It just seemed to wheeze out at about 4500 and lose power. If I lifted briefly and hit the gas again it would shift and accelerate strongly. If I WOT from 15-20, it runs up to 5200 before shifting firmly into 2, 3, 4. Like going onto a long freeway on-ramp.