W203 C180k Oxygen Probe Fault

[tesla]

I have a fault on my 2002 C180K and would be grateful for any assistance the symptoms are:-

The MIL light came on; I got the error code P0130 indicating the upstream O2 sensor/circuit was at fault. I reset the fault but it returned a few days later, further checks revealed:-
Error messages [ignition on engine off]
02 volts bank 1 sensor 1 = N/A
02 volts bank 1 sensor 2 = 0.435V
And on another screen:-
02 volts bank 1 sensor 1 = [WR] 7.995V EQ Ratio 0.999

The top two readings indicate to me that sensor 1[upstream] is not being “seen” by the ECU & sensor 2 is “OK”.
[With engine running the upstream unit remains at N/A and the voltage from sensor 2 fluctuates within the expected voltage range.]
I am unsure what the second set of readings means as they appear to be well outside operating parameters.

So.......... After checking over the wiring between the probe and its plug, I bought and installed a replacement probe................and the readings are still the same

I would be obliged with any feedback relating to the faults above, and suggestions of ways ahead with tracking the fault – before I hand it over to the Dealership - thanks.

 

[Uncle Benz]

The only thing that springs to mind is oil travelling up the wiring loom from the camshaft adjuster magnet on the front of the cylinder head. I know it sounds far fetched, but the oil travels back and drops into the ecu, usually in the area of the lambda sensor circuitry, and creates this scenario. I hope I am wrong!!

 

[television]

The only thing that springs to mind is oil travelling up the wiring loom from the camshaft adjuster magnet on the front of the cylinder head. I know it sounds far fetched, by the oil travels back and drops into the ecu, usually in the area of the lambda sensor circuitry, and creates this scenario. I hope I am wrong!!

Does not the oil also go into the air intake and foul up the O2 sensors, the last one did a few days back

 

[Uncle Benz]

Does not the oil also go into the air intake and foul up the O2 sensors, the last one did a few days back

If this were the case, I would expect the new, replacement sensor to work for a while, at least...

 

[television]

If this were the case, I would expect the new, replacement sensor to work for a while, at least...

Yes I agree, I will try and find the thread, I think that the oil ran down the cable into the MAF

I could be wrong does not the car have 2 O2 sensors