[WRichieX]

Hey guys so I have a situation. So I have a 07 335i e93, recently got an o2 sensor code for post cat. Bought the o2 sensors to replace but looks like whoever worked on this the last time relocated one of the o2 sensors from 4-6 cyl to 1-3 cyl (the pipe where o2 is easiest to get to - I think that's for cyl 1-3) a little more down the exhaust. So I have 2 o2 sensors connected on cyl 1-3. They plugged the original with a bolt or something. Anyone know why someone would do this? As mentioned, everything was working fine until recently with check engine and 2073 code. Hope this makes sense.