[mildbreeze]

I'm seeing an error code 118602 - Oxygen sensor before catalytic converter, fine mixture control: exhaust gas after catalytic converter too lean

The Check Engine Light hasn't come on but it did twice for a day or two and went away during my long trips about a month back. The vehicle is 2016 528i and is completely stock. It's still under warranty and has 41k miles.

Will the BMW dealership diagnose the vehicle under warranty and replace the O2 Sensor even though there's no Check Engine Light? I had the vehicle serviced at the dealer last month and they said everything's good with the car.

Any advise would be appreciated!

[n3985]

Let the dealer handle it since under warranty, their diagnostic can see past and current codes.

[F10_User]

don't even mess with it.
They should cover all costs associated to this.

[mildbreeze]

Thanks n3985 and F10_User for the advise.

I've scheduled an appointment with the service department this Friday.

[mildbreeze]

The dealer changed the sensor and did the reprogramming under warranty at zero cost.

Thanks all for the advise.