4runner

Already bought a Split Second ARM1 for my 2000 supercharged 4runner. The gauge was useless when I bought it, but now the light doesn't even light up sometimes. It only lights up when I hit the gas and it still moves at WOT. I'm thinking about getting a wideband O2 sensor instead from URD, but they sell two different ones. Which one is better? To connect their PLX sensor to my ARM 1 display or buy the Innovative Motorsports one and just have both? I have done all the supercharger fuel mods, but haven't gotten it tuned in yet. Currently, I have set my S-AFC on Gadget's initial settings to be in a safe range.
thanks for your help,
Neil