Hi Matt,
In CA18DET or SR20DET,
When I have disconnect the narrow band O2 sensor plug, the ECU will default show 0.32V or 0.33V in the Nistune O2 signal column,
In the stock O2 sensor signal, 0.32V or 0.33V is equal to 15.5 AFR,
If in the fuel map, all data change to 0 and not using O2 feedback,
Will this voltage actually affact the AFR ?
What I'm thinking is if the default voltage is 0.45V (around 14.7 AFR),
The K valuse will be perfectlly adjusted, match the 0 value with 14.7 wideband AF reading, and 0.45V also match what it should.
Or if the map is full of 0, no matter what voltage reading in the stock O2 sensor signal, the ECU still will not make any adjustment on AFR ?
In SR20DET, if I untick the box of O2 feedback switch, the coulum in Nistune showing 2.48V....this make me confused, 2.48V is rich and same concern, will it pull down the AFR to goes leaner?
O2 singal 0.32V in Nistune......
Moderator: Matt
Hi Louis
Yes 0.3 volts seems to be about the default value shown when the O2 sesnor is not connected
The voltage will not affect the AFR - and probably shouldnt even if O2 feedback flags are enabled (as it only uses the O2 sensor adjustment in closed loop and the signal is not alternating)
If you untick the feedback switch it will no longer adjust the injection based on the result of the O2 feedback in closed loop. Given this the value shown will be reported but have no effect on injection
If you tick the feedback switch the injection will adjust to O2 sensor voltage feedback and this will be observed by seeing the sensor output alternate between rich/lean during closed loop
Yes 0.3 volts seems to be about the default value shown when the O2 sesnor is not connected
The voltage will not affect the AFR - and probably shouldnt even if O2 feedback flags are enabled (as it only uses the O2 sensor adjustment in closed loop and the signal is not alternating)
If you untick the feedback switch it will no longer adjust the injection based on the result of the O2 feedback in closed loop. Given this the value shown will be reported but have no effect on injection
If you tick the feedback switch the injection will adjust to O2 sensor voltage feedback and this will be observed by seeing the sensor output alternate between rich/lean during closed loop