so lemme first start out by saying I'm definitely a beginner learner in upgrading my car.

I have an 08 WRX - ej255 (if that matters) that an ex of mine installed a Cobb cold air intake on awhile ago. He's an ex for a reason and I never wanted to reach back out for advice, but my car has these hiccups when I accelerate a bit too hard. From what I've seen, Id need to upgrade the maf sensor, or just reinstall the stock air filter. I'd like to replace the maf sensor to accommodate for the intake, but is there anything else I'd need to upgrade while doing the maf replacement? I also need to do an emissions test where I live for registration, so would it be best for me to just reinstall the stock air filter and mess with the intake later?

Any and all advice is much appreciated.

edit : i appreciate the feedback and am going back to stock air filter. she's already not in great shape, so just wanna fix her up before any advanced kind of upgrades/mods. and anything involving a tune, im not ready for yet. 😅 thanks everyone!!