99 cougar check engine light code p0155 oxygen sensor?

[justthe6]

i have a 99 2.5v6 cougar 94 k miles. i bought it a few weeks ago. It had a check engine light so i hooked up a scanner to it and it is saying p0155 (heater circut bank 2 sensor 1) I let it run and unplugged the wire to the one that was slow bank 2 sensor 1 and it was the one on the manifold behind the radiator. I took it off and it was black as cole. I bought a brand new one that was OE and installed it, i reset the check engine light and went to live data to make sure the long term and short term fuel trim was doing its thing which it was working great, fluctuating like the rest and the short term trim was really close to zero. I took it out to make sure everything was good while the scanner was still hooked up and after 2 miles it set the same pending code and then in 6 miles it set the check engine light again, with the exact code it had before i changed out the o2 sensor. I d/c the battery terminals and reset it again.. and it did the exact same thing when i drove it afterwards. From here im lost, the p0155 code was all that i had come up on the scanner.. if anyone has any ideas that would be awesome. thanks

[danielsatur]

Are you sure the fuse is good going to the Heated O2 sensor?

[justthe6]

hey there, no i havent checked a fuse, i really didnt know that they had fuses. What does it look like and where could i find it located? Thanks a bunch!

[danielsatur]

I'am not sure, if the Owners, Hanes, or Chilton manuals have the fuse location for the H02 sensors.
See www.alldata.com

[justthe6]

i was able to find the fuse location for the o2 sensors, i checked them and they are all good. I am wondering if the previous owner may have swapped the wiring on that o2 sensor for some weird reason.

[justthe6]

today i went out and printed out the wire schimatics on the car, i was able to clarify that the wires on the engine o2 side were in the right places on the plug. i hooked up a power probe to each of the four wires on the o2 sensor plug and tested them individually, i was getting a signal and power on three of them, but the ground that goes directly to the PCM had no signal when the car was turned off or running... does this mean automatically that my PCM is going bad or is there other possibilities??
thanks

[justthe6]

YAY! PROBLEM SOLVED! I went out today originally to test the ground wire that wasnt getting a signal at the PCM, i double checked all of the wiring under the hood and discovered that the main plug near the righthand side of the firewall was barely holding into the other half, the clip itself wasnt getting a good connection (i found out this is a ford problem) i used a ziptie for the time being to squeeze it together until i can find a new plug, i reset my check engine light, i drove it 30 miles and all of my monitors set and i was able to go get an emmisions test today!

[danielsatur]

The tie wrap will probably last longer.
Clean connector with CRC electronic cleaner, use a tie wrap, and sealent for protection.