[ujorgan2000]

G/Day everyone, help needed please. How many 02 sensors are they on a 2001 E39 530i with M54 mill under hood, and any one changed or have link to good DIY thread. All help, advice much appreciated.

 

[edjack]

There are four: two pre- and two post-cat. I believe your pre-cat sensors are accessible from the top of the engine compartment, on the right side.

They are as easy to change as spark plugs. If you've never changed spark plugs, take the car to a mechanic.

 

[16valex]

+1 ^^^

 

[ujorgan2000]

Thanks Edjack, you have been most helpful.

 

[bluebee]

Look in the bestlinks for the word 'oxygen'.

You'll find this, among others ...

- Oxygen sensor DIYs (540 M62) (525 M54) & locations (1) & O2 sensor tools you can make at home (1) or borrow for free (1) & all about 02 sensors (1) & eliminating the rear o2 sensors (1)

 

[SeanPhang]

I did it on my car several months ago. The job itself is very easy, but I found reaching for the 2nd sensor at the back a real PITA, because the space is too limited and also the sensor is sitting tight in place.