Big SF vs Stock..

Hey guys,

I’ve been chasing some unstable AF Learning and AF Correction numbers on my 2021 WRX and decided I’m going to remove my Cobb Big SF Intake, reinstall the stock airbox/filter, and get the car retuned at Prime Motoring.

Symptoms:

•	DAM stays at 1.00

•	WOT seems fine

•	Idle and cruise trims tend to go positive

•	Learning creeps up during steady driving

•	Corrections fluctuate more than I’d like

It feels like airflow/MAF scaling instability more than anything mechanical. I’ve adjusted filter placement before and it helped slightly, but trims still don’t seem as stable as I want.

My question is — has anyone gone back to the stock intake and seen trims settle down significantly? Did it clean up your idle/cruise learning?

Just trying to see if others have gone this route to fix unstable AFR behavior and whether it made a noticeable difference.

Appreciate any input.