Ford: 1994 FORD EXPLORER 4.0L 4x4, wire spray, shell gas

Question
(134K mileage) Recent EEC readout on an intermittent indicator to check the engine resulted in memory codes 181, 186 and 189. Indicator comes on briefly, usually when asking for more velocity when climbing a hill or passing another vehicle, then goes off. Historically, the O2 sensor has been replaced, but the light still comes on as it did. Plugs are good. Engine runs otherwise fine. Exhaust system checked fine. Suspect fuel injectors, fuel pump, or fuel filter. Any other thoughts? PCV? Too much oxygen, still?

Answer
what i would do is remove the maf sensor look inside it and you will see a small thin wire spray this with only brake cleaner then reroad test it .if this take care of your problem then if it happens again you have to replace it.also ck for vac leaks this would make it run lean and cause a o2 sensor code. ck air filter , and by all means DO NOT use shell gas. let me know good luck