In my quest to find a solution to the EGR problem we discussed at length in this thread
Hyundai I30 1.6 CRDI - errorcode p0404 EGR-Valve. Please help 
, I went ahead and checked the upstream O2 sensor with a multimeter (OEN 393504A410).
The connection plug looks similar to the one in the picture. Voltage measurements of each lead are:
1. 1.95 V
2. 2.5 V
3. 12 V
4. 12 V
5. 1.95 V
6. 2.67 V
These voltages were stable at idle, 2500 rpm and with key on, engine off. No fluctuations whatsoever.
From my research, I think the signal wire is nr. 6 and it should be somewhere between 0.1 V and 0.9 V and it should fluctuate. Or am I wrong?
I drove the car for a bit with the sensor disconnected, and there was no change. It had the same symptoms as before, and the check engine light did not come on. I checked for logged codes with my obd2 bluetooth adapter and found only one code... I forgot the number, but the description said oxygen sensor heater circuit high voltage. Nothing else...
Anyone out there in possession of normal specs for this part? Do you think the PCM might be faulty? I would appreciate some help
