ThunderMax Oxygen (O2) Sensor Operation Testing User Manual
O2 sensor testing, Diagnosing a problem in the o2 sensor system
O2 Sensor Testing
If your engine has unexpectedly started to run poorly, an O2 Sensor Test should be
performed.
IMPORTANT:
Testing the O2 sensors using the procedures below REQUIRES that the engine will idle normally and
with reasonable stability. This must be achieved by loading the original base map or a known good base map and
clearing ALL learned conditions.
After reloading the base map and clearing all learned conditions, if the engine does not idle reasonably well,
the probability is VERY HIGH that there is a mechanical or electrical issue on the motorcycle causing the problem.
Refer to:
Trouble Shooting Basics if engine will not idle properly
Diagnosing a problem in the O2 sensor system
1. Load the original “un-modified” base map to the module.
2. Clear “Learned Fuel Adjustments”
3. Clear “Learned Idle Adjustments”
4. Perform module initialization of Key ON 20 sec, Key OFF 20 sec….repeat 5 times.
5. Start engine and let idle to operating temperature.
AFR readings while the engine is idling normal and stable
AFR value is constantly 19.36 on “one cylinder only”. Other cylinder AFR reads normal.
O2 sensor is faulty.
Wire harness is damaged.
AFR value is constantly 19.36 on “both cylinders”.
O2 module is faulty.