You might ask yourself why you want to replace the piston. I just did a top end job on my 99 220, and I have kept track of the total miles on it. At almost 5,000 miles, the piston snd cylinder were both still within specs, although the rings were worn. Also, my local dealer parts tech could find no aftermarket pistons for the 220, so you might have to get a stock one anyway.
More likely, your KIPS valve and componenets will need decarbonizing, and like the previous poster said, be careful to keep track of where everything goes.