id get a better cold air feed going into the air box. how you choose to do this is up to you but id run an alloy or larger pipe down towards the bumper. Yeah the MAF is the aluminium part in between the air box and throttle body. i gave the inside of mine a good soak in carb cleaner and made a smoother tick over.
Spend your money on a replacement panel filter for the air box, ie k&n.