Error Code

March 11, 2009

Hi guys,

Hoping that someone can help me.

Engine warning light came on again, took it to a mate who's a maechanic. He plugged in his gadget and got the following error message, "P1155 A/F SENSOR HEATER CIRCUIT FAULT B2-S1".

So, what is this, how much will it cost to fix and can I run it okay in the meantime?

Thanks in advance.

March 11, 2009

Yes, its the oxygen sensor that needs changing. I think bank 2 sensor 1 is the top r/h side of the exhaust (please check first). They are slightly more expensive than the lower ones but are available from the net for about £80 and really easy to change.

Your car should still be ok to drive. Some people never change them but the light permantly on can mask other more important faults.

March 11, 2009

Thanks, I'll need to have a look under the bonnet tonight. Do you need any special tools to remove the sensor (don't know what it looks like)?

March 11, 2009

Thanks, I'll need to have a look under the bonnet tonight. Do you need any special tools to remove the sensor (don't know what it looks like)?

It looks a bit like a spark plug. You can buy a proper sensor removal socket with a cut-out for the wire. I got a draper one from my local car spares shop for £5. I think the top ones are easier to get to so you may be able to use a ring spanner. You need a 22mm one.