What are the common causes of P0161?

An open heater element in the bank 2 sensor 2 oxygen sensor. A blown heater fuse. An open in the heater feed or ground on sensor 2. A failed heater relay. A faulty ECM heater driver.

Check the oxygen sensor heater fuse. Measure the bank 2 sensor 2 heater resistance. Test the heater feed and ground at the sensor. Replace bank 2 sensor 2 if the heater is open. Check the heater relay. Clear the code and retest.

P0161

O2 Sensor Heater Circuit Bank 2 Sensor 2

System: Fuel and air metering (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P0161 means O2 Sensor Heater Circuit Bank 2 Sensor 2.

Where it lives

For P0161, the circuit described runs through the sensor. The description of P0161 puts it on bank 2.

Check these first

An open heater element in the bank 2 sensor 2 oxygen sensor
A blown heater fuse
An open in the heater feed or ground on sensor 2
A failed heater relay
A faulty ECM heater driver

What to do next

Check the oxygen sensor heater fuse
Measure the bank 2 sensor 2 heater resistance
Test the heater feed and ground at the sensor
Replace bank 2 sensor 2 if the heater is open
Check the heater relay
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.