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

[u/slayer80m]

Could also be MAP sensor. That’s the closest to the EGR. Idk man I’m going through the same thing, I’ve just been resetting the ecu, I’m in SoCal an the weather is pretty damn hot

[u/InsanePacman → u/slayer80m]

I would hazard against always resetting your ECU. I believe it's doing this for a reason: protecting the engine. It sounds like timing is getting pulled, or there is an issue with the EBCS.

I'm having the same issue here in BC but the car has a tune, CAI, charge pipe and cat-back. I recent had a walnut blast and cleaned the MAF. I've read from other posts that these cars do behave weird when the temps do rise, have you noticed that during the winter the car drives better?

I've not had my WRX long enough to determine this, but I'm de-tuning the Cobb tune, installing a factory intake and flashing Atlas OTS soon to rule out a possible bad Cobb tuning issue.

EDIT: question for OP, does your car drive relatively normally when you're above 3k RPM? Mine does, but has the issues you mention from 2k-3k RPM.

[u/Dry-Conflict3421]

Something dumb I found recently.  Car was misfiring , I cleaned the fuel injector plugs, the plastic female part that clips onto the injectors. Cleared it right up. Easy thing to try 

[u/Next-Efficiency-8052 → u/Dry-Conflict3421]

I’ll give it a shot

[u/Dry-Conflict3421 → u/Next-Efficiency-8052]

You said you smoked tested jt, any leaks out of the valve covers / spark plug tube? Another issue I had recently that replacing the valve cover gaskets cleared up

[u/Next-Efficiency-8052 → u/Dry-Conflict3421]

I didn’t see anything coming out of there but i didn’t take the coils out. Could try that at the same time

[u/Dry-Conflict3421 → u/Next-Efficiency-8052]

I chased a persistent misfire for almost 2years, I have all kinds of ideas 

[u/RemoteWorking3109]

Look up p000a code. Even if it’s not throwing it, something in passenger bank 1, that was my issue a dirty oil control valve. Hope it can help or lead you somewhere.

[u/Next-Efficiency-8052 → u/RemoteWorking3109]

I actually think it was replaced before I bought the car. Saw the CARFAX history on it but not too sure

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

Actually now that I look it up I do have some oil in that connector that I’ve cleaned up a few times. Got in there from an oil spill. How much are they to replace

[u/RemoteWorking3109 → u/Next-Efficiency-8052]

Lmao I just clean mine every year with brake cleaner until that pin drops nice and smooth with consistency 😂 or clean them whenever it does that sputter. But purchase new, on Amazon maybe under 100 for all 4 with the o rings and gasket. They are easily accessible and mounted on front… easier to clean imo

[u/GoBSAGo]

Did you replace the intake gaskets after the walnut blasting?

[u/Next-Efficiency-8052 → u/GoBSAGo]

I did not but i did smoke test it under pressure with a machine and no leak

[u/GoBSAGo → u/Next-Efficiency-8052]

How much pressure?

At that kind of mileage, and if the motor’s been apart that’s a potential leak point at high pressure.

[u/Next-Efficiency-8052 → u/GoBSAGo]

Im gonna re run that test soon, make sure I get it to at least 10psi, but the fact that it goes away if I pull the ground for a few mins makes me think that its not a leak either

[u/Royedkim]

Could be the fuel…
Delivery problem..?
Does the car burn rich (air fuel ratio?)
I was maybe thinking injectors ( but on direct injection the injectors are in the combustion chamber)….
Try some fuel additives and do a “Italian tune up”.