MAF sensor cleaning made a big improvement!
Just wanted to comment in case it's helpful to anyone (particularly novice owners) else here.
I have an NC2 Sport with stock 2.0 and no engine mods. For a while, I was getting a bit of lugging when letting off the clutch, especially when cold. At times, the struggling sound would pain as I could envision it damaging internals. I'd slightly rev the engine a bit and slowly let out the clutch with some success, but none of this was ideal.
I thought the issue might be that I was running higher profile tires (Cross Climates) on larger rims (PF-01s) at a high altitude which affects the speedometer and was rubbing sometimes before I modified the wheel well skirts.
Anyway, before, investing in a second set of wheels and tires, I figured I'd try cleaning the MAF and throttle body. It was a super easy task, but requires a few precautions (such as only using MAF cleaner, ensuring it is completely dry before reinstalling, and not over torquing the screws). I accidentally bought two cans of MAF cleaner, so I used that on the TB, which probably wasn't very effective, but it didn't look very dirty anyway.
The thermistor was dirty on the intake side. After cleaning both parts, letting it dry for 30 minutes and reinstalling, I noticed an immediate change -- for the better. No more shuttering or hesitation! I was expecting some rough idle etc while the ECU relearns the clean sensor, but I didn't notice it.
Hope this helps!