O2 sensors for OEM Euro Headers

[DropTopKingM3]

Hey guys, I recently picked up a set of Euro headers and euro cats. I wanted to have new O2 sensors installed when I install the headers.

Before taking advantage of black friday deals, Id like to make sure I have the correct P/Ns before I order.

BMW Oxygen Sensor - Bosch 13949 | FCP Euro
BMW Oxygen Sensor - Bosch 13952 | FCP Euro <- this is the one Im unsure of. Some say Bosch 13951 but realoem says 13952

These are the ones that go on the header (precat) correct?


Also, would it be wise to change the O2 sensors on the euro cats (post cat) as well?

Thanks in advance.

[Cubieman]

Hey guys, I recently picked up a set of Euro headers and euro cats. I wanted to have new O2 sensors installed when I install the headers.

Before taking advantage of black friday deals, Id like to make sure I have the correct P/Ns before I order.

BMW Oxygen Sensor - Bosch 13949 | FCP Euro
BMW Oxygen Sensor - Bosch 13952 | FCP Euro &lt;- this is the one Im unsure of. Some say Bosch 13951 but realoem says 13952

These are the ones that go on the header (precat) correct?


Also, would it be wise to change the O2 sensors on the euro cats (post cat) as well?

Thanks in advance.

Those are the correct sensors for pre-cat, just went downstairs to check the boxes as I replaced them when I did my headers.
I would say to go ahead and change out the post cat sensors if you have any doubts as they are no longer accessible in the Euro sec. 1 without dropping the exhaust.

[DropTopKingM3]

Cubieman you my friend are awesome! Thank you.


The post cat sensor P/N's I found were:
13951 and 15138

Are these correct for post cat?

Thanks again!

[Cubieman]

Cubieman you my friend are awesome! Thank you.


The post cat sensor P/N's I found were:
13951 and 15138

Are these correct for post cat?

Thanks again!

Unfortunately I don't know the part #'s for the post cat sensors, I didn't replace them when I did the Euro setup. I figured I could replace those without dropping the exhaust, not the case as I found out.

[Slideways]

Post-cats only measure cat efficiency. If they are not throwing codes, I'd save the money for something else.

[Cubieman]

Post-cats only measure cat efficiency. If they are not throwing codes, I'd save the money for something else.

So only the EGT sensor is responsible for cat protection?

[Slideways]

So only the EGT sensor is responsible for cat protection?

Yup

[DropTopKingM3]

Yup

Thank you for the useful info. Would you recommend changing the egt sensor?

[Slideways]

Thank you for the useful info. Would you recommend changing the egt sensor?

Not really. It is not that significant to engine operation and it is easy to change out when it fails.

[DropTopKingM3]

Not really. It is not that significant to engine operation and it is easy to change out when it fails.

Thank you! Youre always a great help

[mrgizmo04]

Precat bank 2 sensor and postcat bank 1 sensor have the same key/plug, so watch those when you are connecting everything to avoid misfires post header job.





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