[ali.golfam@gmail.com]

Hi All

A few months ago I got an engine light on and scanned anf got the following errors:

- 118602 Oxygen sensor before catalytic converter,system checksignal fixed at rich
- 128301 Oxygen sensor before catalytic converter,fine mixture controlexhaust gas after catalytic converter too lean

So far I have changed my MAF Sensor, Engine Air Filter Na both upstream Oxygen Sensors and still get the same error everytime temperature goes above ~+2°C.

I have not noticed an increase in fuel consumption however I do smell fuel from my exhaust. Anybody has any idea what could be the issue?

[Subydayo]

Originally Posted by ali.golfam@gmail.com

Hi All

A few months ago I got an engine light on and scanned anf got the following errors:

- 118602 Oxygen sensor before catalytic converter,system checksignal fixed at rich
- 128301 Oxygen sensor before catalytic converter,fine mixture controlexhaust gas after catalytic converter too lean

So far I have changed my MAF Sensor, Engine Air Filter Na both upstream Oxygen Sensors and still get the same error everytime temperature goes above ~+2°C.

I have not noticed an increase in fuel consumption however I do smell fuel from my exhaust. Anybody has any idea what could be the issue?

This post might be of some interest to you: https://f30.bimmerpost.com/forums/sh....php?t=1847944

I would definitely start by measuring the fuel trims.

Also which F25 do you have? 28i? 35i? It would also be good to include mileage, and as much info as possible really.

[ali.golfam@gmail.com]

It's a 28i. Mileage is ~240,000 KM.

Understanding that the engine is running lean but I can smell gas/oil coming from my exhaust. not very intense but I got a strong sense of smell and can pick it up.

Attached are photos of the codes I'm getting.

FYI some of the work has already been completed with no result:
-New MAF sensor
-New Air Filter
- The O2 sensors were checked and no oil on them
-Smoke tested and no leaks were found.


Photos are provided in the link below.
https://ibb.co/2WL1FhH
https://ibb.co/FmTPnXT
https://ibb.co/M9SjZYT
https://ibb.co/XtJCD1S
https://ibb.co/dkr0ndX
https://ibb.co/LpBB0cS
https://ibb.co/gd3scpv

Would appreciate it if anyone has any similar issues. I took it to multiple mechanics and they can't seem to find the issue.

[Subydayo]

Have you made sure all the spark plugs are working? If there's too much gas then that is running rich.

[Gryga]

Hey i have same problem . Maybe you find what it was problem ?

[383vett]

Just to make sure, you did clear the codes?