Trouble Code came UP

[Nowhereman]

Just drove home from work and my "service engine light" came on.
Seems it's a P0161 "O2 Heater circuit" Bank 2 Sensor 2.
That's an O2 sensor is it not?

[cpop98ws6]

9 times out of 10 it is a bad O2. I would clear it and see if it comes on again, if it does then I would change it.

[Nutball]

Just drove home from work and my "service engine light" came on.
Seems it's a P0161 "O2 Heater circuit" Bank 2 Sensor 2.
That's an O2 sensor is it not?

did a lil homework here for ya, hope it helps. This covers a variety of autos, but it does cover Pontiac

Possible causes
- Faulty Rear Heated Oxygen Sensor Bank 2
- Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks
- Exhaust gas leaks

Replacing the O2 Sensor 2 usually takes care of the problem (Like Cpop98 said )

When is the code detected?
Current amperage in the rear heated oxygen sensor heater circuit is out of the normal range


Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible higher than usual fuel consumption

P0161 Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

[Too Fast]

Assuming nobody has jacked with any wiring/modified things, (since you're in that communist state the loves/hates cars, yours is most likely not modded) then yes 97% chance the O2 went bad. Yes the fix is a new one.

[Nowhereman]

It was the passenger side #2 O2 sensor.
Swapped it out; 70 bucks for a Bosch unit with OEM plug.
No more idiot light.
Not bad, 1st one in 126k miles.
She's roaring around town again.

[35th-ANV-SS]

You're lucky it lasted that long. Most get lazy way before 120K miles.