Yes, I have the custom aircraft exhaust; three into one collector. The O2 sensor is located in the #6 stack so there are no leaks, just exhaust gas.I tried the O2 sensor in my early setup and tuning and despite multiple sensors and controllers could never get anything even remotely close to consistent readings. My running hypothesis is that the multiple slip joints on the Rocket exhaust was simply letting too much outside O2 in and polluting the readings. Does your 10 have a ”tight“ gas path from cylinder to sensor?