How do I fit a wideband AFR to 940 2.3T?
 

I want to add a wideband AFR to my 940 2.3T B230FK.

How do I do this?

Do I need a different ECU or can I plug one into the stock ECU.

Do I need a different or extra lambda sensor?

Any advice would be gratefully received.

The stock ECU will not help you, and I'm not sure why you think it could, can you do this in other cars?

The Stock ECU doesn't really have much output ability, like you can with ODB2. You can hook up some RS232 to it, if you know how to wire it, but it is limited.

Generally a wideband sensor needs a controller that matches it and that it is calibrated to. The output of the controller can then be connected to a suitable compatible gauge. Sometimes gauges and controllers are combined.

So basically you need a standalone system to read the AFR, costs about £100+. Add another bung to the downpipe and screw in the new sensor, add power and hook it up to your gauge.

Alternatively you can use the narrowband sensor with a cheap gauge, or just use a graduated boost gauge and stay below 12psi, you should be ok.

AEM Uego wideband is a nice bit of kit, approx £170 but the later no-calibration-needed Bosch LSU 4.9 sensor.

It has an output to feed back into an ECU, but highly doubt you can make the standard ECU do anything with it. It'll just show the ratio realtime for tuning purposes.

Perfect thank you. So it looks like an aftermarket ECU would be required.

If you just want an AFR readout you just buy a standard stand alone AFR guage and sensor kit. An Aftermaket ECU will not provide that.

If you want to run your engine leaner more often, make it easier to tune with a wideband providing feedback to the ECU etc you need an aftermarket ECU and wideband sensor. You could then monitor it via EOBD/ODB2.

An aftermarket ECU is over £600, then you have to fit it, usually by wiring everthing directly, there are no drop-in kits with socket adaptors yet for the 940s.

I'm after fitting an AFR gauge to my 940. Can anyone recomend a decent one ? Thanks.

All you need https://www.ebay.co.uk/itm/NEW-AEM-X...kAAOSwsO1aslfJ

Note you'll need something like that to feed an aftermarket ECU with the right signal anyway!

That looks perfect. I assume you'd just need to fashion an exhaust piece for the O2 sensor?

You are looking for a weld-in Bung with the right thread in it, can't remember the M but pretty standard for O2 sensors. And a drill/hole cutter the right size for the bung.