2001 300M Code P0161 Back After Sensor Change
I'm new to the forum guys but I have researched all the old threads I could find on this issue. I still have a few questions though.
Here is the situation: 2001 300M 3.5L V6. Check engine light on, Code p0161, 2/2 O2 Sensor Heater Failure. I bought a new sensor, NTK 23133, and installed it in the drivers side, after cat position. Fired up the car and check engine light was still on. Shut it down and started it again. Check engine light not on. HOORAY !! Problem fixed.
Well..... For 3 days it was. Check engine light is back on and Code P0161 is back.
Is my new O2 sensor bad? Possibly, I have not ohm'd out the new sensor heater yet.
Could this possibly be a fault in the PCM? I understand there have been some issues with this PCM throwing bad codes.
It just seems strange to me that I had the light out after the sensor change and 3 days later the exact same code is back. I did not cancel the MIL with my scanner, it went out on it's own after the 2nd start, after the sensor change.
I have heard also that a bad catylitic converter can cause faulty O2 sensor codes, but I would think the heater circuit would not be one that is caused by that.
Anyone with experience on this, I would be very appreciative af any info. any of you have.