Check engine light

[sjroost]

Hi Everyone,
I have a 2009 VE commodore Omega. I have had the check engine warning light come on in the last 12 months of the last 2 years I have had the car. I have had all 4 02 sensors changed. the warning returned and now 2 different mechanics have said that its the sensors and I am not convinced. they were replaced 12 months ago, it cant possibly be that again. There has been no change or difference in the fuel economy, it runs well except for the light always coming on. the first time I took it to the second mechanic he said the code that came up was: PO 430 CALALYST OFFIENCEY B2.I took it to him again for a service and for the light and it came back with the code: P0 420 and P0 430 Catalyst Efficiency B1 S1 & B2 S2.
has anyone else had this happen? what did the problem end up being? I am thinking I need to take it to Holden, haven't wanted to cause of what they can charge but I don't know of any other option. I have read on forums here that it could be the exhaust gasket. does anyone have any suggestions or ideas? any feedback would be greatly appreciated. thank you

 

[Sabbath']

2 different mechanics have said that its the sensors and I am not convinced. they were replaced 12 months ago, it cant possibly be that again.

Wouldnt be so sure of that.

 

[kwaka738]

Have a read of this thread (and sub thread). It might be relevant.
http://forums.justcommodores.com.au...2006-2013/223510-engine-error-code-po430.html

 

[sjroost]

Hi kwaka, thanks for the thread. I read that one too that's what made me think it was the exhaust gasket. Might just take it to holden and see what they say.

 

[sjroost]

Hi Sabbath, what makes you say that?