rusefi.com

Hi Guys.
A 2-cylinder motorcycle has 2 narrow-band lambdas, 1 for each cylinder. Is it possible to configure this config programmatically? As far as I know, one lambda is usually placed on all cylinders before the catalyst and one after the catalyst, but here an unusual solution is used. And, if we take uaEFI as a basis, can I use any unused analog inputs for them?

I don't have a rusEFI yet, but exploring configurations in tunerstudio. This Ecu has at least 2 "banks" to do lambda correction. In your case you could use one bank per cylinder.

uaEFI has only one build in lambda controller. You can add https://www.shop.rusefi.com/shop/p/uawbo over CAN. Or AEM gauge if you like it.
Unfortunately wideband sensor is more complex device than narrow and you need controller not analog input.

Also you may prefer MicroRusEFI + dual channel wideband https://www.shop.rusefi.com/shop/p/dual-channel-wbo . Both can be packed to waterproof enclosures, that makes some sense on bike.

molak wrote: ↑

Sat Nov 08, 2025 5:19 am

I don't have a rusEFI yet, but exploring configurations in tunerstudio. This Ecu has at least 2 "banks" to do lambda correction. In your case you could use one bank per cylinder.

Oh! Thanks, it looks like this is exactly what I need in my case. All that remains is to figure out where to physically connect them

Dron_Gus wrote: ↑

Sat Nov 08, 2025 6:25 am

Also you may prefer MicroRusEFI + dual channel wideband https://www.shop.rusefi.com/shop/p/dual-channel-wbo . Both can be packed to waterproof enclosures, that makes some sense on bike.

Yes, microRusEFI is a good choice, but after comparing it with uaEFI, I still decided to opt for uaEFI, redesigning its circuit and board to suit my needs.
Unfortunately, I cannot use broadband lambda probes at the current stage. The idea is to make an ECU for a motorcycle that could be mounted on a motorcycle without any modification. Narrowband lambdas initially come from the factory, so I'm focusing on them, although wideband ones certainly have an advantage.
If we talk about narrowband lambdas, is this supported by the rusEfi project, or is it easier to use an open loop and not focus on lambda readings?

n6b044vr4 wrote: ↑

Sat Nov 08, 2025 7:25 am

Yes, microRusEFI is a good choice, but after comparing it with uaEFI, I still decided to opt for uaEFI, redesigning its circuit and board to suit my needs.
Unfortunately, I cannot use broadband lambda probes at the current stage. The idea is to make an ECU for a motorcycle that could be mounted on a motorcycle without any modification. Narrowband lambdas initially come from the factory, so I'm focusing on them, although wideband ones certainly have an advantage.
If we talk about narrowband lambdas, is this supported by the rusEfi project, or is it easier to use an open loop and not focus on lambda readings?

Ok. If we talk about narrow band sensor with 0..0.9V output - you can use any analog input.
But AFAIR we just removed all code related to narrow sensors used an closed loop and focused on widebands. But you can still log these inputs, see its raw voltage in log viewer and so on.
You can also do some Lua magic to read these narrow sensors, decode values and do some checks or even "fake" wideband AFR inputs to get some benefits of STFT and LTFT. But this is definitely out of developers interests and you will have to walk this way alone.

Got it, thanks. I'll think about how to make it easier.

I am using the rusEFI UAEFI on my '95 Jeep. I understand the UAEFI121 has 2 WB O2 circuits.