1986 Ford LTD wagon 3.8 TBI - not running right

~82K miles. Same vehiccle as in the other thread of mine. Ran decent until about 3 weeks ago.
Problem started overnight - literally.
Idles rough, drives rough, and fells like it occasionally wants to cut out under moderate acceleration. Fuel milage was kinda crappy before, and still is (350+ miles per tank when the car was younger, now it's lucky to break 200 since it's came out of retirement)
Plugs are new, wires & cap appear solid, fuel filter's new. Checked the fuel pressure - 38PSI and steady under idle. Vacuum lines appear good and seat firmly.
I don't remember the exact codes, but they translated as:
1)EGR position sensor out of range
2)system lean
3)right O2 sensor lean
Those were the -only- codes, from a quality Snap-On handheld unit.
Pos. sensor replaced w/ new, comp. cleared to re-learn - no change in symptoms or codes.
EGR cleaned thoroughly - as above.
EGR replaced w/ one from a local parts yard, used the new sensor, comp. reset - no change in symptoms, but haven't checked for codes yet.
I'm guessing that I'll have to break down and change the O2 sensors (the symptoms are a good fit), but I'm open to (and hoping for:lol: ) something else to try.
Thanks in advance!!

Have you checked your fuel pressure regulator? You could also try cleaning your fuel system with some "sea foam" through the pcv valve. Hope that helps, good luck.

Haven't checked the regulator yet, since the fuel pressure readings I was getting at the throttle body appeared rock-solid and steady. Haven't done Seafoam through the PCV, but I have ran 2 cans through the tank. No noticable improvement.
What I did do that helped some was changing the distributor cap & rotor. Plug wires are next when I get some time. I decided on this when I saw that it ran worse during damp/wet weather. I guess that looks aren't everything.:lol: