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Mini Cooper 2007 non-turbo.
So the P2414 fault code keeps appearing, despite me replacing the pre-cat O2 sensor with a Bosch item. I've carried out continuity checks between the sensor and the ECU an it looks fine.
Anyone experienced this before?
I've got pretty good diagnostic software which I can use in graph mode. Does anyone know what signals I can monitor in order to properly diagnose this?
Looks like I've found the issue. The B connector on the engine ECU is filled with coolant. I've been informed that leaking coolant can be drawn up through the ECU harness by capillary action. I've dried it and cleaned it out and the O2 sensor is now giving the correct voltage. Hope this helps anyone with similar O2 sensor issues.
Here's copy of my post elsewhere. I'm posting it here because you asked about AFR:
2009 Base R56
Throwing a P2414 Code. Torque OBDII app shows: O2S1Eq = 2,00, AFR = 29.38, Vacuum 23.30, O2S1C = 1.7mA, O2S2V is normal (.1 to .9)
When I pump the brakes the AFR goes down as do the other O2S1 Readings. When I remove the brake booster vacuum, the AFR goes down as do the other O2S1 Readings, then return to the high readings even with the vacuum disconnected.
The fact that the readings go down, seems like the sensor is working OK. I plan on pulling and cleaning the pre cat O2S1 sensor anyway.
Replaced Upstream O2 sensor with Bosch. Problem solved.
Also fixed a problem that I had for a long time where the car would lug when I accelerated in high gears. Apparently, an O2 sensor can be faulty without throwing a code.
