Wide band EGO sensor: useable?

[Ludotech]

Hello,

Today I read this in this forum:

You need the controller, MegaSquirt (or MS-II) do not have a built-in WBO2 driver at this point.

I didn't know this!

So, If I plan to use a wide band O2 sensor, I MUST buy a WB controller, am I right?

However, the EGO input of MS II (pin 23 of DB37) supports a signal from 0 to 5 V, so MS II can "read" the signal from a WB EGO sensor but this signal is unusable(but viewable with megatune?)?

Am I right?

[Bernard Fife]

MS II can "read" the signal from a WB EGO sensor but this signal is unusable(but viewable with megatune?)?

Ludotech,

Not quite. The wideband sensor needs a controller to adjust it's equilibrium point. The amount of current required to achieve that equilibrium indicates the air/fuel ratio.

You need a controller to provide that current, and it has to provide the current while measuring and maintaining the equilibrium. So it is a fairly sophisticated circuit, and one that does not existing in MegaSquirt (or MS-II).

So you need a controller to:

a) drive the sensor to an ever-changing equilibrium, and
b) convert the current required to do that into a 0-5 Volt signal.

Without a controller, a wide band sensor is essentially just two narrow band sensors hooked together in the same case...

Lance.

[Ludotech]

Ok, so a wideband without the controller is unusable, I'm going to study the working of this type of EGO sensor before asking another stupid question!

Thank you Lance.

Ludovic

[Bernard Fife]

Ludovic,

No problem, if you are interested, there's some background here: http://www.megasquirt.info/PWC/

Lance.