I had the same problems during the dyno runs with the O2 sensor and monitor I got from Tracy.  Replaced the O2 sensor with a heated sensor (three lead) they had at the dyno connected to their computer readout and everything worked fine.  I wasn’t sure if it was the sensor or the monitor but I guessed it was the sensor.  My O2 sensor is installed in a custom muffler about 18” downstream from the manifold.  Haven’t tried a new sensor with the EM2 yet.  Where did you place the O2 sensor?

Al

Hi Al,

The problem appears to be the sensor (see next post).  My O2 sensor is just before the muffler, about 40" downstream from the rotors. 

Rusty