Code Definition

P1146 — Heated Oxygen Sensor 2 bank 1 voltage low

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Infiniti

About P1146

P1146 is a manufacturer-specific powertrain diagnostic trouble code recorded for Infiniti vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1146 is stored, the module has detected a signal or supply voltage lower than the expected operating range; a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1146 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The heated oxygen sensor 2 on bank 1 is the rear, post catalyst sensor on the bank containing cylinder number one. The Engine Control Module (ECM) uses it mainly to monitor catalytic converter efficiency by comparing its slow, steady signal against the faster switching of the front sensor. DTC P1146 sets when the ECM detects that this rear sensor signal is biased low, holding toward the lean end of its range. This may result from a real lean exhaust condition, a contaminated or aged rear sensor, an exhaust leak near the sensor, or a signal or heater circuit fault. The malfunction indicator lam...

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