WBO2 = wideband oxygen sensor [& datalogging]. I have the Innovate Motorsports LC-1 WBO2 and OT-2 OBD-II scanner and datalogger and I love it. It requires an iphone/ipod; I use an android phone now, but older used iphones are CHEAP. I keep an iPhone 4 around just to use with the OT-2.

I can't recommend running stacked pulleys without fuel rail and fuel regulator upgrades. It might be ok, but I am very conservative about these things. I would definitely NOT try it on the stock pump. The important thing is to monitor your air/fuel ratio with a wideband O2 on the street or, even better, tune at a trustworthy dyno shop with one.

I upgraded the fuel pump and regulator just to run the 62mm pulley. I modified the rail, upsized the lines (again) and went to 550cc injectors to go to stacked pulleys.