Gary, I have a O2 bung welded into both of my header reducers. I am currently learning with one sensor in the drivers side reducer. My plan is once I get some tuning time with one sensor, I would like to buy a second gauge for the passenger side just so I can watch both sides. Is it overkill for the second sensor? Maybe, but I would not know for sure until I install it or move my existing sensor to the other side.
