R1000
Registered
I've been running with a PC III and disconnected stock O2 sensor since the PC III was installed. The O2 sensor eliminator has been plugged in. The A/F ratio has been nice; about 13 to 1 but on some loads like light cruising the A/F ratio has been just below 12 to 1. This could of course have been tuned but the bike has run very fine, strong and responsive over the whole rpm range so I haven’t bothered to change anything.
This weekend I reconnected the stock O2 sensor to see how it will interact with the PC III. In theory the bike will then run leaner on low loads and part throttle and the PC III will come into control at higher rpm's and throttle openings. This was also exactly what happened. The power is still there at WOT, where the A/F-ratio is 12-13:1. But under light load it is now typically about 14.5 to 1 and even 15 sometimes.
The change could be recognised already when taking off, the bike sounds softer and is definitely less responsive on low rpm's. So the conclusion is that eliminating the stock O2 sensor and use the PC III gives better power over the band, at the cost of high fuel consumption at cruising. An easy fix would be to use a switch that disconnects the O2 sensor and connect the 330 ohm O2 sensor eliminator resistor for best performances, and switch on the O2 sensor when low fuel consumption is in priority.
Edit: If the O2 sensor is in place but disconnected from the ECU, the sensor heater should probably still be powered to avoid fouling it.
This weekend I reconnected the stock O2 sensor to see how it will interact with the PC III. In theory the bike will then run leaner on low loads and part throttle and the PC III will come into control at higher rpm's and throttle openings. This was also exactly what happened. The power is still there at WOT, where the A/F-ratio is 12-13:1. But under light load it is now typically about 14.5 to 1 and even 15 sometimes.
The change could be recognised already when taking off, the bike sounds softer and is definitely less responsive on low rpm's. So the conclusion is that eliminating the stock O2 sensor and use the PC III gives better power over the band, at the cost of high fuel consumption at cruising. An easy fix would be to use a switch that disconnects the O2 sensor and connect the 330 ohm O2 sensor eliminator resistor for best performances, and switch on the O2 sensor when low fuel consumption is in priority.
Edit: If the O2 sensor is in place but disconnected from the ECU, the sensor heater should probably still be powered to avoid fouling it.
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