Hi there,
I have a 2003 Disco with 110,000 miles. Recently, the CEL came on. Got the codes from Auto Zone: P0154 and P0174. I guess I need to change all 4 O2 sensors! Based on the forum, it sounds like I need to change them all at the same time. Am I correct?
Does anyone have a link to a step-by-step directions on changing the sensors? I really would like to do it myself and save some money!!!
Any help is greatly appreciated.
Thanks
Bob

 

You should change all 4, yes, but that may or may not correct the lean run on bank 2.
Rover connection has about the best price for the 02 and they are fairly easy to replacing, usually only needing a little penetrating fluid to break up the rust.

 

Thank you Mike. It sounds like it is not a terribly difficult job but do you have a link that shows how to change the sensors? Also what are the possible reasons for my other lean run on bank 2? By the way, the CEL is now off but it's just a matter of time for it to come back!
Thanks again for your help. It is greatly appreciated.
Bob

 

Could be the 02, if not then you would want to look at the engine for vacuum leaks or a MAF that is starting to fail.

 

Thanks again... Can anyone tell me where they are located and how long do you think it would take to replace all 4 O2 sensors?