# how many O2 sensors are there in a 528 (e39) and where are they all located?



## jtg (Oct 9, 2003)

^^ :dunno:


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## McCandless (Oct 3, 2003)

You didn't specify what year 528 but on my 99 there are FOUR. Two in front of the catalytic converter part of the headers (exhaust manifolds) (Cylinders 1-3 and 4-6) and two after.


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