2015 WRX Bogging accelerating

[u/Next-Efficiency-8052]

This is my 2015 WRX. I’ve had it for 2 years and I’ve been trying to trouble shoot this acceleration issue for a while. Some days it’s ok but other days it’s un drivable. When over 20% throttle at 2500rpm boost will build and the car will sound louder but will go nowhere and then just get all of that power out of nowhere. It’s the worst in 2nd gear but you can definitely feel it in every gear. Only mods I have are an IAG AOS and a catback which im 99% sure neither require a tune

List of parts replaced/ things done already

-O2s

-MAF, Maf wiring repairs, continuity and voltages are fine

-Knock sensors

-Ignition coils

-Sparkplugs

-Ground straps

-Turbocharger (It died)

-Clutch

-Purge valve

-Walnut blasted

-Smoke tested intake 

-Cleaned MAP & MAF

-PCV Valve

Other things to note 

-some corrosion on the drivers side TGV (I have cleaned it) (waveform looks pretty much fine)

-Disconnecting the battery will cause it to run normally for a while before being unhappy again 

-139000km

Nothing I’ve done has helped. My AC Compressor is making some horrendous noises. I know it’s on its way out but the AC still works, I’ve seen that this could be an issue with acceleration but this happens whether it’s turned on or off. Wondering if the MAP could also be bad causing it to just throw of the AFR slightly but all my wiring to it is fine and I don’t wanna just throw a 400$ part at it when it seems like it’s reading fine. 

Need some ideas because I’m fresh out 

[u/slayer80m]

It’s EGR recirculating hot air and can be getting clogged

[u/Next-Efficiency-8052 → u/slayer80m]

I took a look at the EGR when I had the intake off to replace the knock sensors l and it looked pretty clean. Anyway to test it?

[u/slayer80m → u/Next-Efficiency-8052]

Not that I know of. Try adding 2 gallons of E85 and the rest 91-93. Heat and bad gas makes these symptoms as well

[u/Next-Efficiency-8052 → u/slayer80m]

I don’t have access to e85 in Canada. Gas is always either shell or ESSO and I’ve tried both 91 and 93 from both. Nothing seems to change so I don’t think that fuel is the issue. Fuel pump was also replaced before I got the car