Re: 954 Airbox mods, ram air, air filter. What works?
Yeah, you'll have to get the O2 sensor plug. Just part of dealing with 1 state bikes. Stick with the OEM filter, the others do nothing for gains. The best bang for the buck exhaust is the Hindle, not near as pricey as the Arata.
The PAIR is the system that takes a touch of fresh air from the airbox and inject it into the exhaust port to help emissions. It will give a false reading when tuning the bike unless plugged off. Might as well just remove it. No performance gains or losses, but it's worth a few pounds off the bike.
I'd skip the shift star, maybe do the spring and arm kit, but the star really isn't necessary.