What Does P0164 Mean?
The ECM has detected that the bank 2 sensor 3 oxygen sensor is producing a voltage above the expected maximum. This indicates the sensor signal is stuck high (above ~0.9V) or biased rich. Sensor 3, when present, monitors exhaust downstream of a secondary catalytic converter. A high-voltage reading could be caused by a sensor fault, a wiring short to voltage, or an actual rich exhaust condition at that location.
Common Causes
40%
Failed O2 sensor with internally shorted or contaminated sensing element
25%
Signal wire shorted to the heater power wire or another voltage source
15%
Coolant or oil contamination of the sensor tip from an internal engine leak
15%
Saturated or failed catalytic converter passing excess hydrocarbons
5%
ECM input circuit fault pulling the signal high
Diagnostic Steps
1
Monitor bank 2 sensor 3 voltage in live data. A reading stuck above 0.9V or at the sensor's maximum voltage suggests an internal sensor fault or wiring short.
2
Disconnect the sensor and recheck the voltage at the ECM harness side. If the voltage drops to near 0.45V (bias voltage), the sensor is the problem. If it stays high, the wiring has a short to power.
3
Inspect the O2 sensor connector and harness for melted wires, pinched insulation, or cross-contamination between signal and heater circuits.
4
Remove the sensor and inspect the tip for white (coolant), oily black (oil), or sooty deposits that indicate contamination from an internal engine problem.
5
Check catalytic converter outlet temperature vs. inlet using an infrared thermometer. The outlet should be 50–100°F hotter; a cold converter or minimal temperature rise suggests converter failure.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
The ECM has detected that the bank 2 sensor 3 oxygen sensor is producing a voltage above the expected maximum. This indicates the sensor signal is stuck high (above ~0.9V) or biased rich. Sensor 3, when present, monitors exhaust downstream of a secondary catalytic converter. A high-voltage reading c...
The most common cause of P0164 (02 Sensor Circuit High Voltage (Bank 2 Sensor 3)) is: Failed O2 sensor with internally shorted or contaminated sensing element
Typical repair costs for P0164 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving in the short term. Sensor 3 is a monitoring sensor and does not directly control fuel delivery. If the root cause is coolant or oil contamination, however, the underlying engine issue should be addressed promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0164 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Fuel System / Emissions
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
