Wideband Sensor Testing
Turbo Mini Forums

My Legacy has a fault code that leads me to believe on of the O2 sensors is bust, trouble is it has four of the buggers and I'm not changing them all.

The two behind the cats ar narrowband and I can test these with a meter, but can I test the widebands?

I have access to lots of fancy scopes etc just not sure what I should be looking for.


cheers

Wil

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Wil I don't think you'll be able to diagnose a fault unless you know how the controller on the car is driving it.

The simplest diagnosis is going to be ot borrow a 3rd party controller to see what's going on.


Nial.

Kind of what I was thinking. The current fault code is P0240 Catalyst System Efficiency Below Threshold.

As it has been intemittant over the last 12 months I'm hoping it's a sensor rather than a cat. And using logic, my guess is that it's the ones past the cat rather than in front, as the front ones do all the fuel metereing.

I'll measure the rear ones and see what they look like.

Cheers

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

I tend to agree with Nial but even then it's not that simple - there are three generic types of LSU (sensor) used with third party controllers. Apart from them having three different plugs - which sort of makes it a bit easier - the third party controllers have to be configured differently for the different types before they will operate them correctly. With the TechEdge that I use, it means altering jumpers inside the box for one of the types, the other two just need different calibrations.

But, there is no guarantee that an OEM LSU will conform to, or even be wired as, one of the generic ones.

Lots of information on the TechEdge website if you want to experiment...

http://wbo2.com/lsu/lsuworks.htm

Start here and work backwards..... :)

Schrödinger's cat - so which one am I ???

If its bosch, you should be able to wire it up to the VEMS controller. No calibration needed as they work like an OEM system works. make sure you get the wires correct. There is some usefull information on vems.hu Wiki

I did this with the sensor from the wifes Arosa after the garage replaced it as faulty. Would you believe that the sensor was infact perfectly ok, and the initial probloem still persisted. I like it when the garage manager starts to flap wen you can methodicaly prove anything they have done or will ever do is amature

Your thinking is the same as mine. I don't want to take it to the garage with a fault that could be one of two catalitic converters or one of 4 lambda sensors. at best they'll keep changing them til the fault goes.

at least I can rule out two simply.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph