suburmabn

Need help with 05 WK, 3.7L. DTC P0161 – O2 sensor htr circuit malfunction. Connector at the sensor burnt up and shorted against the CAT. I replaced the connector and O2 sensor but still get a P0161 code. I swapped the two downstream CAT sensors and the code didn’t follow the sensor (still P0161) so I know the problem is in the circuit. I also swapped the relay with the same AC relay and still got P0161. I ran the tests in the Factory Manual and got the following results. With KOEO the voltage on the brn/gy wire at the sensor harness connector was .72V and shows continuity. When I start the car, the voltage goes to 11.17V and then drops to approximately 7V-8V after a few seconds. Resistance between the C-3 connector at the PCM (pin #10, brn/gy wire) and the #2 pin at the sensor connector (same brn/gy wire) was 2.1 ohms. Resistance between pin #1 at sensor harness and ground is 9.8 to 11 ohms. This resistance should be less than .5 ohms so it indicates a problem. Is there anything I can by-pass or jumper to see if this drops to .5 ohms. The bk/grn ground wire from the sensor heater connector routes around the back of the firewall and is impossible to access to check for a short. Any help or advice is appreciated. Thanks, Scott