Code P0161 OS Heater circuit

[Ketch]

99 Suburban 2wd 5.7L r code:

I have an INNOVA scan tool that read P0161 code which is a fault for the passenger side oxygen sensor, the one after the CC. Says bank 2, sensor 2 heater circuit or some such. This is a fault of the heater circuit that drives the oxygen sensor. I can not find a fuse for this so I assume there is not one.

I was getting this error before when I found coolant in the oil. So I fixed the intake manifold gasket (again) and it has not leaked in 1000 miles or so. The idiot light came on last week with this code as the suspect.

My freeze frame data reads as follows:

Fuel system 1 closed loop - fault.
Fuel system 2 closed loop - fault.
Calc. load 7.4%
Engine coolant temp. 181F
STFT (fuel trim) Bank 1 0.0%
LTFT Bank 1 - 4.6%
STFT Bank 2 0.0%
LTFT Bank 2 - 6.2%
Intake manifold pressure 15.3 in/hg
RPM 608
Speed 0 MPH
Mass airflow sensor 2.24 LB/Min
Throttle position 7.4%

The only thing I think I understand is the LTFT negative 6.2 per cent means it is reading rich fuel trim long term.

I read many threads to try to understand 02 sensors and some imply 02 sensor may not be the fault itself. Does this data tell anything?
BTW changed fuel pump same time as intake manifold gasket.

[Ketch]

yesterday battery went dead. After I recharge the battery, the SES light was gone. Does the computer lose memory when the battery goes or is disconnected?

[2000CAYukon]

Originally Posted by Ketch

yesterday battery went dead. After I recharge the battery, the SES light was gone. Does the computer lose memory when the battery goes or is disconnected?

Yes. Most likely the code will come back.

//2000CAYukon