2.3L ('83-'97) 96 Ranger 2.3L Constantly Switching from Open Loop to Closed Loop

[SenorNoob]

The only way I can see it running that rich on all cylinders is if the air is super restricted (like new filter still wrapped in plastic, lol), the FPR is leaking (unlikely it'd hold pressure), or maybe the injectors are stuck open.

 

[ksimp]

Just in case anyone is interested, I'm attaching a FORScan capture.
Thanks

 

[ksimp]

@SenorNoob ,
My guess is the one or two fuel injectors leaking caused the upstream O2 sensor to carbon foul (see uploaded pic). So, it was unable to read oxygen content properly, thus giving a false rich reading. The replacement O2 is responding as expected (with the rebuilt injectors).
I did follow @franklin2 's advice and added seafoam to the gas tank. Maybe I added too much?
Thanks

 

[franklin2]

It will smoke if you add too much, though the catalytic converter might hide that.