Q on Lambda -- aftermarket standalone ECU

[Jellybean]

From factory the car has a narrow band sensor , adding the wideband ; will this make the OE narrow band obsolete or would the ECU still make use of the OE narrow band?

 

I presume unplugging the OE unit will have zero affect to the ECU

[Mike2JZ]

On a stock ECU you must run a narrowband for the ECU to be able to have any closed loop control of fuel trims. You may add a wideband, however the stock ECU will not interface with the wideband. The wideband in this instance is under manual user monitoring to decide if the engine is running to lean or rich.

 

On a standalone ECU it is usually expected that you will run a wideband sensor rather than a narrowband as your Oxgen/Fuel ratio source. Usually because the wideband has more resolution (0.5 to 1.5 Lambda) than a narrowband and is a bit quicker to react. I have yet to come across a situation where I need a narrowband instead of a wideband. I would say for most Supra's going standalone, the stock narrowband sensor becomes obsolete and is ok to unplug/delete etc.

 

That said, most standalone's will support the use of a narrowband sensor, but again I have not seen many cases where this is the preferred option.

 

I've noticed that more modern performance cars are coming equipped with multiple wideband sensors from the factory.

[Jellybean]

Thanks