So I have 2.5 inch equal length headers and up, the stock turbo, and a 3 inch catless tbe. Also a 3 inch cai and perrin turbo inlet on my 04 wrx. Never had any problems till recently. My afr's are suddenly running at 14.7:1 from idle tapering to about 12.8 at 3500 rmps and at about 4000 it drops to 11.1:1 roughly and stays strong there all the way to redline. I have the cobb ap and racetuner (I tune the car myself) and have run logs and everything other than the afr is fine. It trips a system too lean code bank one and suggest a coil wire or plugged injector so I replaced the wires and cleaned the injectors and none of that helped. A friend suggested larger injectors and a new fuel pump and my mechanic/tuner friend suggested 750cc injectors. Do my mods support that much fuel? Would that even it out to a decent 11-11.5:1 after proper tuning? So far we have been unable to tune this problem out and my only other thought is to go back to the stock intake. If that would be better.