Hello Peeps,

 

I am new to this site so hello to all!

 

I am after some help please. Skoda Octavia - code P242A exhaust gas sensor 3 on bank 1 seems to be throwing up errors. I have done a DPF clean and regen and nothing works so I suspect the sensor has given up the ghost!

 

QQ; how do I locate which sensor it is? I can see at least 3 and I can see a fourth and potentially fifth under the car!

 

I have watch some many youtube videos and even downloaded the cars diagrams but no joy!!! Any help will be greatly appreciated as I need an MOT ASAP as I am off on holiday end of this week! It failed me at the last minute. 🙂

 

Cheers,

 

BDonks

Using a generic scan tool is not gonna be much help here sorry 

 

Fault codes contain a ton of data that can be read by more specialised tools and help diagnose the fault. Things such as short to ground, short to power and such.

 

As it’s a temperature sensor it can be tested with a multimeter to see if it’s open circuit and replaced if it is 

@ApertureS

thanks for your comment but I think you misunderstood. I know what the issue is I just can’t tell which sensor it is or where it is located and two of the sensors are on one plug sensor 1&2. A lot of experts have not even been able to find it! So I was merely trying to see if someone else on this site had the same experience and may know where it is located on the exhaust?

9 hours ago, BDonks said:

@ApertureS

thanks for your comment but I think you misunderstood. I know what the issue is I just can’t tell which sensor it is or where it is located and two of the sensors are on one plug sensor 1&2. A lot of experts have not even been able to find it! So I was merely trying to see if someone else on this site had the same experience and may know where it is located on the exhaust?

Out of interest how do you know it’s faulty?

 

and to find it if you really are sure it’s that one, simply unplug a sensor and check what code appears, plug it back in and clear and do this till you find sensor 3. You only have bank 1 as it’s not a V engine so chances are it’s the furthest back sensor after the DPF. 
 

I believe the temperatures sensors are; one in the turbo, one pre dpf, one post dpf. The other sensors you talk of are going to be oxygen sensors and NOx sensors 

 

its hard to say without me knowing your engine code.

 

 

 

or it could be complete opposite problem and your scan tool is incorrectly reading a fault code (which happens a lot) and it may not even have a sensor 3 and you’ll need to read it with a more advanced tool.

Edited 29 June, 20232 yr by ApertureS

The MOT centre did a full test on their machine and my diagnostic tool brought up the same code so they both can’t be wrong, no?

4 hours ago, BDonks said:

The MOT centre did a full test on their machine and my diagnostic tool brought up the same code so they both can’t be wrong, no?

You use a generic scan tool, and I'm guessing the MOT centre did too?  A generic tool usually won't give the detail needed to point to a specific sensor, you really need a scan with a VAG specific tool such as OBD11 or VCDS to give the detail.

@PetrolDave I did but no they didn’t they have very sophisticated equipment and even service and MOT high end vehicles. Thanks for your help and input Dave!