I have no luck with o2 sensors :)

Bosch wbo2 sensor ( p/n: 0 258 017 030/031, VW 06E 906 265C )

It looks like "17 025" sensor ( ), and the pinout is the same. It is likely to be an LSU4.9 sensor (not the same pinout as LSU4.2).

I found some info on page.

The problem is that I can't do the free-air calibration. The highest o2 value was ~18% while the wbo2 calibration constant was 255...

What config (or HW) changes should I try ?

Everything is the factory recommended settings.

Pump zero pw, and nernst target values are ok.

I'm afraid that I'll kill the sensor...



Config taken from here: but on test bench MT reads (fast changing) random voltage (2-5V).

  • Found the cause of the problem(?): There is a squre wave at the ADC7 input, it is coming from OC2 pin (atmega pin 17) thru C62 and R137.

The truth is, noone used nbo2 sensor for 4 years. To start the engine it's not needed. To tune the engine it's not suitable.

So everyone just sells nbo2 sensor and swaps to wbo2, the only reasonable way. If you can start the engine, don't tune before you have WBO2. It does not worth the risks. You can checkout order via IBAN and pay later.

(note: wbo2 sensor hasn't been sent, as you were hesitating and said hold until you ask owner. Orders must go through webshop, not phone anyway)