I've been running a PCIII on my '05 since I first got it 5 years ago
This winter was an extremely mild one, so I was able to ride all winter. But, my fuel mileage was pretty poor (below 40 mpg). It has since recovered somewhat (back up to 40-42 mpg) now that we are back on the summer fuel mix, but it got me thinking that maybe I could go back to
not using a PCIII and hooking back up the O2 sensor and get better mileage. So, I zeroed the PCIII's map and hooked the sensor back up and, man oh man... the bike runs like crap! I even tried raising up the CO settings a little at a time, as much a 10, which does help some, but the bike still stumbles and jerks due to the lean fueling when the O2 sensor goes closed loop. Went through a tank of fuel and can't really see much mileage difference.
I'm going to raise the tank again today and disconnect the O2, and load back in my preferred map.
Speaking of maps, I got a copy of a custom map from another '05 owner that had it created on a Dyno for him. It has worked much better (smoother) than the maps that are available from DynoJet or the Wally map. You are free to give it a try to see if it works for you too. You can download a copy here:
Stock '05 FJR PCIII Map by Ryan Schnitz Tuning