Oxygen sensor test?

[uk174]

Hi All,

I have a 2003 skoda octavia 1.8T Elegance estate that I bought a while ago. Yesterday the engine management light came on and and after having it code read I have the following codes on it..

17522

16524

17522

17526

All of which relate to oxygen sensor bank 1 sensor 2. however my question is that from what I can see in the paperwork this sensor was replaced in August 2015,surely it should last longer than this?

I have been told that one can check the sensors by measuring the resistance across their pins.Does anybody now what the resistance should be across a good sensor and what pins to attach the multimeter to?

I would be very grateful for any feedback. Thank you in advance for your help.

[kentphil1]

Those codes are not so much for the sensor itself, but more for the heating circuit for the sensor. as this is built into the sensor, it often means a new sensor, even though its primary function to read the oxygen rates is functioning fine.

 

I must admit that the sensors do not appear to be as robust in their design as they used to be, but this is not just a criticism of Skoda , as my daughter's 05 1.4 Ford Fiesta has the lambda fault code again for the second time in 18 months requiring a new sensor

[Ade VRS]

Invest in a good quality sensor and you should have no problems. These cheaper chinese ones are more trouble than they're not worth!

I had a Bosch sensor in my Impreza for 4 years with no issues.

[uk174]

Invest in a good quality sensor and you should have no problems. These cheaper chinese ones are more trouble than they're not worth!

I had a Bosch sensor in my Impreza for 4 years with no issues.

thank you.

 

Those codes are not so much for the sensor itself, but more for the heating circuit for the sensor. as this is built into the sensor, it often means a new sensor, even though its primary function to read the oxygen rates is functioning fine.

 

I must admit that the sensors do not appear to be as robust in their design as they used to be, but this is not just a criticism of Skoda , as my daughter's 05 1.4 Ford Fiesta has the lambda fault code again for the second time in 18 months requiring a new sensor

thank you.However can I test a sensor by measuring it resistance across certain pins?

[SuperbTWM]

You should be able to measure across the heater. If its open circuit you know its a gonner, but if there is still some resistance you need a good sensor to determine what you should be expecting

Edited 3 June, 2016 by SuperbTWM

[Tech1e]

There are also common issues with wiring under the battery tray area.

[Breezy_Pete]

Heater of bank 1 sensor 2 is between pins 1 & 2 of the sensor, as far as I can make out. The pins that the blue/red and grey/yellow wires connect to when the loom connector is plugged in. Something makes me think single-figure Ohms should be the ballpark you're hoping to be in, or maybe just into double-figures. As said above, an open-circuit or high-Ohms reading would indicate a broken heater inside the device.

[uk174]

Heater of bank 1 sensor 2 is between pins 1 & 2 of the sensor, as far as I can make out. The pins that the blue/red and grey/yellow wires connect to when the loom connector is plugged in. Something makes me think single-figure Ohms should be the ballpark you're hoping to be in, or maybe just into double-figures. As said above, an open-circuit or high-Ohms reading would indicate a broken heater inside the device.

Hi,

 thanks for the input.Have had a mechanic friend quickly look at the sensor plug with a multmeter and he reckons there is no power to the heater circuit at all.Reckons he will now check to see if the sensor heater circuit is connected to any fuse, on the assumption that there may be a fuse blown that is causing the eml to come on as sensor maybe not getting up to working temp?

Are you aware of any such fuse that may be causing this?

[uk174]

There are also common issues with wiring under the battery tray area.

Hi,

 Thanks for the input. What exactly do you mean when you say that? What does one need to look out for?

[uk174]

You should be able to measure across the heater. If its open circuit you know its a gonner, but if there is still some resistance you need a good sensor to determine what you should be expecting

 

You should be able to measure across the heater. If its open circuit you know its a gonner, but if there is still some resistance you need a good sensor to determine what you should be expecting

Hi,

 thanks for the input.Have had a mechanic friend quickly look at the sensor plug with a multmeter and he reckons there is no power to the heater circuit at all.Reckons he will now check to see if the sensor heater circuit is connected to any fuse, on the assumption that there may be a fuse blown that is causing the eml to come on as sensor maybe not getting up to working temp?

Are you aware of any such fuse that may be causing this?

[Breezy_Pete]

Seems to be fed (along with a couple of other things) by fuse 243, a 10A fuse. Not sure where that would be on an Octy though I'm afraid.

[Tech1e]

Fuse 43 right hand side of the dash.

[uk174]

Fuse 43 right hand side of the dash.

thank you

[uk174]

Seems to be fed (along with a couple of other things) by fuse 243, a 10A fuse. Not sure where that would be on an Octy though I'm afraid.

thank you