code P0156 HO2S

Hello to all. I have a 1999 3.8L w/ 158k Miles, failed emissions test, ( i think the guy read the code, & didn't go any further.) I have one month to repair and retest at no charge. I checked the sensor according to my haynes manual.Ii 'm getting 0.11 volts on the signal wire hot or cold. I suspect the PCM. Is there a way to test it. Please help I only have two weeks left. Thanks.

I think your PCM is fine something in Bank 2 O2 wire and or O2 sensor most likely bad. Did your CEL come on before your inspection.? could be just wire is old and the O2 shot.. I would try getting a reading on the others and see what you fine..Not unless something else is going on to make you think the PCM is bad. You would get a 601 or other codes if that were the case...

That is the downstream sensor for bank #2.
Bank #2 is the Front bank of cylinders.....closest to the radiator.
Downstream means that the sensor is downstream (after) the catalytic converter.

I would put the front wheels up on ramps, Place the transmission in PARK, set the parking brake and block the rear wheels.
Then go under and find the exhaust pipe from the front bank of cylinders.
Follow it back.....and behind that catalytic converter (you have 2 catalytic converters, 1 for each bank of cylinders) you will find the oxygen sensor.
I would follow the wires from that sensor.....inspect them for any sign of damage...make SURE that they are NOT touching any part of the exhaust system....which would melt the insulation on the wires......and be a very likely cause for the code you have.
I would then unplug plug that you will find in the wires from the sensor....it will be a little distance from the sensor.....inspect the inside of the plug for signs of corrosion.
I would also spray some contact cleaner in the plug and plug it back in.

If none of this turns anything up, you might try moving the downstream sensors from bank to bank.
NOW, on my '96, one of the downstream sensors was mounted into the rear of my catalytic converter.
If that is the case on your '99, and it is for Bank #1, you might want to just leave it be, and buy a new oxygen sensor for Bank #2.
When I was changing my "Y" pipe on my 96, the sensor mounted into the rear of the catalytic converter broke out of the thin metal shell of the converter, threaded part and all....which would have been a not fun thing, had I not been changing the unit anyhow.