Code help - 119702

[SlimM5]

Greetings fellow enthusiasts.
Check engine light came on today on the ride to work, but no messages popped up in the car.
When I got home, I plugged in the ole trusty Carly and ran some diagnostics and this code, 118702, came back for O2 sensor.
I know our cars have several sensors, but this one came back as before catalyc converter.

Is this common? Is this sensor code accurate? And where exactly would I find this sensor?

Any help is appreciated. Thanks!

[ECB]

These are the pre cat O2 sensors right in the center of the pic:

[M5_Raz]

Yep, what ECB said. They’re the easier ones to change out. You can buy the tool kit at o’rielly (you need an extended thin walled socket).

[M5Rick]

The only decision now is if to buy BMW stamped ones, cost more for peace of mind or the Bosch.

[ECB]

I've always used the Bosch MAFS and O2 sensors without issue.

[SlimM5]

Originally Posted by M5_Raz

Yep, what ECB said. They’re the easier ones to change out. You can buy the tool kit at o’rielly (you need an extended thin walled socket).

More information on this tool kit . . . Do I just mention to them that I need tools for 02 sensor removal?

[SlimM5]

Originally Posted by M5Rick

The only decision now is if to buy BMW stamped ones, cost more for peace of mind or the Bosch.

Given my luck with maintenance lately, I may opt in for the BMW stamped ones for peace of mind and minimal issues if warranty service is needed. My codes did not read which sensor, so is it best to change both?

[M5_Raz]

Originally Posted by SlimM5

More information on this tool kit . . . Do I just mention to them that I need tools for 02 sensor removal?

https://www.oreillyauto.com/detail/c...set/ren1/67060

Pretty sure it was this one!

[SlimM5]

Originally Posted by ECB

These are the pre cat O2 sensors right in the center of the pic:

This pic helps a lot. Thank you!
Looks easy enough. I did reset my codes and the CEL has not returned. I'm still going to order the replacements just in case.

[SlimM5]

Originally Posted by M5_Raz

https://www.oreillyauto.com/detail/c...set/ren1/67060

Pretty sure it was this one!

Thank you!

[M5Rick]

Originally Posted by SlimM5

Given my luck with maintenance lately, I may opt in for the BMW stamped ones for peace of mind and minimal issues if warranty service is needed. My codes did not read which sensor, so is it best to change both?

As you say for peace of mind and over here you get 2 years warranty on BMW fitted and genuine parts, that's why I had spark plugs done at my favourite service dealer when car was going into 'drive moderately' when pushed but then I was pushing it at 40k on the originals.
BMW stamped parts are less likely to fail. Yeah I'd change both.

[SmokinJoe]

I’ve had that same code and my auto logic scan tool says it’s ‘118702 oxygen sensor before catalytic converters 2 fine mixture control: exhaust gas after catalyst too lean.’ I’ve changed primary sensors with Bosch units. Didn’t work for me so I have something else going on. Keep us posted on what happens when you change them.

[SlimM5]

Finally got around to changing the precat O2 sensors. Opted for the Bosch sensors; for cost savings. So far so good. If it doesn't work out, then I'll just reach out to FCP Euro for warranty coverage and purchase the BMW O2 sensors. Haven't had a chance to put the ride on throttle since the change, so will report back how it feels.

The sensor for bank 2 seemed to be extremely chalky.

But so far, so good, after clearing the codes. No more CEL.