09 Skoda Fabia Mk2. I have had the car a short time. EML light comes on. OBD11 shows it as P0135 O2 sensor heater circuit. Wipe the code and a day or so later, it returns. So I unplug the sensor on top of the engine. The resistance across the sensor heater (two white wires) is 8 ohms. A little high perhaps but it seems OK. I then test the voltage across the two pins that I have unplugged from with the engine running and there is 13v. Where do I go from here?

Hi, welcome.

 

is your OBDEleven program for your model and year of VW fully updated?

 

Do bear in mind generic codes or other error codes can point you in the direction rather than always finding the culprit. are you sure 8 ohms is fine, have you done wiggle, heat/cold tests, looked at live data? - https://club.autodoc.co.uk/obd-codes/p0135

 

You may find more information by look at or posting on the Fabia and/or Fabia Mk1 forums. - 'Škoda Fabia' (forums). - https://www.briskoda.net/forums/forum/166-škoda-fabia/

 

Thanks for the reply. Further investigation on the forum indicates that the sensor is probably at fault. If so it isn't a cheap fix but possibly better than having to go through the wiring like Sherlock Holmes looking for a fault.

If buying a sensor get genuine stuff, VW part numbers on many parts, as a general rule Japanese is better than German or others (often from China) and VW or Tosch maybe Japanese once out of the box.  Tosch superseded part or multi-fit park might (or might not) be alright but check with other 2009 Fabia Mk2 owners.

 

Replacing the part is only better than chasing diagnostics if it is the part at fault.

 

Good luck.