05mustang

i have tried the active diag mode and it passes.

I have a 92 legacy wagon, it has almost no power and strugles to get to 3000 rpm, worse cold. it has 30-40 psi fuel pressure, spark plugs and fuel filter are new. It has no codes. I disconnected the air flow senor and and it ran better. I replaced the maf with a new one from subaru. The car ran great for 4 days and then started to run poorly again. I have also cleaned the fuel injectors with a professional injector cleaner kit. from 3000rpm up it seems to run normal. Any help would be great.