02 snesor change E39

[skoff]

I had the orange 'check engine' light pop up on my car yesterday. Having plugged my OBD2 reader in it gave me a P0155 code which is 'Oxygen O2 Sensor Heater Circuit Malfunction (Bank2, Sensor1)'

So I am guessing the first port of call is to change the O2 sensor, is this a tricky thing to do and is there anything else I should be worrying about?. It's a 2001 530i if that makes any difference?

[skoff]

Hmm, interestingly, after a few days the warning light has gone off. Does anybody have any guidance on whether I can just ignore this now? Is it likely to be a typical E39 sensor glitch?

[mini1380cc]

By the sounds of it you have a dodgy pre cat O2 sensor on the last 3 cylinders. It sounds like it is intermittently failing at the moment, when it does go the car should run rich costing you more in petrol.


If you do decide to replace you should buy Bosch, not the ebay jobs.

[skoff]

I have a 22mm o2 sensor socket on order following a bit of Internet research saying it makes the job a lot easier, so will probably change it in the next few weeks.

Thanks for the advice on the best make to buy.