P0300 diagnostic code o2 sensor circuit

[Johnfc2017]

Hi,

 

My parent's Skoda Fabia is in the garage after a service and MOT, the car had the o2 sensor replaced because I had diagnosed that as a possible issue and they carried on driving it so it needed a new cat. After replacement, the car showed no errors and passed the emissions test with flying colours and then the engine light came back on and diagnostics came back with P0300.

 

The garage is reputable, we take all our cars there but the garage owner called me completely stumped because they tested the wiring and the sensor and traced all the wires to the ECU, reset the ECU with their fancy and expensive scanner yet this car keeps returning the same fault.

 

So does anyone have any idea what would be the problem? The garage think they should take it to Skoda to see if the ECU needs a software update or something. It's a 2010 Skoda Fabia Mk2 trim level 3, one of those TSI 1.2L engines.

[sepulchrave]

http://wiki.ross-tech.com/wiki/index.php/16684/P0300/000768

 

Please explain, unless you've been given the wrong fault code.

[Johnfc2017]

Okay, got the car back so I could run diagnostics and two faults: P0030 (the garage must have read the code too quickly) comes up on basic ODB2 and 06342 comes up on Engine on my Carista. I reset them both and the check engine light went away but the codes are still showing up.

[sepulchrave]

http://wiki.ross-tech.com/wiki/index.php/16414/P0030/000048

 

Ok, that correlates.

[sepulchrave]

1 hour ago, Johnfc2017 said:

Okay, got the car back so I could run diagnostics and two faults: P0030 (the garage must have read the code too quickly) comes up on basic ODB2 and 06342 comes up on Engine on my Carista. I reset them both and the check engine light went away but the codes are still showing up.

 

I can't find any reference to the 06342 code that Carista is showing you, please double check.

[Johnfc2017]

Carista reported 06342 - Manufacturer specific code. Whatever that means?

[rum4mo]

Quote "Manufacturer specific code." that usually means that Carista have not (yet) included that code in their app, if you contact them via email or FB they usually put in a bit more effort and come up with the correct meaning.

 

Some cheaper diagnostic tools just add in a bit of spice to your fault tracing/finding, which is not what you expect.

[sepulchrave]

I think we can safely ignore the spurious code, I agree that the next step will be to escalate to the dealer for a firmware update, it won't be expensive.