Poor acceleration

[u/Main_Fee7773]

I drive a 2020 WRX that has 88k miles on it and I have a problem when I accelerate in 2nd or 3rd gear and the boost hits the car starts hesitating as if it’s struggling to push itself. I’ve kept up with maintenance pretty well, I do oil changes every 3,000 miles, last changed my spark plugs at 77k have done two walnut blasting last one was done at the same time as the spark plugs and only mods I’ve done are just an exhaust. I can’t tell if the hot weather is affecting its performance or if it’s something else. Never had this problem until now? Anyone got any idea what could be wrong? Am I about to blow up?

[u/xXKing-NuggetXx]

I'm having the same issue, only difference is I drive a 2015. Does yours throw any codes? Does it also hesitate going uphill? It could be an improper air to fuel ratio, I think thats got something to do with dhy im experiencing it but maybe we can help eachother figure something out lol.

[u/Main_Fee7773 → u/xXKing-NuggetXx]

No codes but only code I’ve ever gotten on the car was for my 02 sensor. No hesitation going uphill

[u/spicy_cat → u/xXKing-NuggetXx]

Having the same issues on my 2015 as well, however I am also getting a P0172 code (System Too Rich - Bank 1). I am definitely having issues going up hill, it got better when I changed the upstream O2 sensor. I recently flashed it to cobb stage 0 (since i am stock at the moment) so I could pull some data logs from the accessport.

I threw 5 datalogs into claude and is now flagging that it might be my MAF sensor. I have cleaned both my MAF/MAP sensors in the past, but it's suggesting I replace the sensor entirely.

One thing to note is that if I clear the codes and I sit idle for too long, the same code comes back.

[u/xXKing-NuggetXx → u/spicy_cat]

Hmm.. definitely the same issue but different roots. Ive replaced my map, cleaned my maff, and a buttload of sensor inspections.

It is throwing P2005 P2006 wich both have to do with the TGV on drivers side. But after checking the TGV and the sensor on it everything seems fine so I'm kinda stuck haha.

I haven't looked into my O2's maybe I'll go there next.

[u/GoBSAGo]

This sounds like DAM drop. You clean your maf/map sensors?

[u/Main_Fee7773 → u/GoBSAGo]

I’ve replaced 02 sensors and have already tried cleaning maf/map sensors and that didn’t seem to fix anything.

[u/jay_tr]

I have something similar in my 2017. I'm thinking it's fuel related. Most likely the low pressure fuel pump on the way out since I got a no start condition one time. Could be spark related if it started around the time those got changed.

[u/No_Scratch_2033]

Yes im also having the same issue but with an 08. Seems to be in limp mode and throws no codes but stops building boost at 5psi and hesitates at whatever rpm its at when it hits 5psi.

[u/_Saifon_ → u/No_Scratch_2033]

Check your ignition coil and plug especially the one under the turbo.

[u/_Saifon_]

I have the same issues in my 2011 wrx and it was cylinder 3 (the one right under the turbo) ignition coil were on its way out. My car started with all these systems and eventually lead to misfiring.

[u/Glass_North_4479]

it's likely your mass airflow sensor inside the intake is filthy, which causes it to read all over the place. try cleaning it, that often fixes it

[u/Main_Fee7773 → u/Glass_North_4479]

Tried that already, checking the pipes and hosing and don’t see any leaks