over the weekend my 99 nsx popped a check engine light. i havent driven it since before today when i went right up to my buddies shop. with the light still on he hooked up the scanner and it said that bank 1 was running rich. it suggested checking the o2 sensors. we did so as to the instructions and the o2 sensor gauge on the scanner fluctuated between .15 and .85 at 3k. it did so kind of slow compared to other cars i have seen on the scanner and did not mention which sensor in bank one we were measuring. the scanner also mentioned lists of other alternatives to the o2 sensor that could be wrong w/ the car. btw, i have in the last month had the thermostat replace because the car was running cool. does anyone have any suggestions before i waste all his time chasing down these random diagnosis?