Code Definition

P1133 — Heated Oxygen Sensor RH front insufficient switching

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

About P1133

P1133 is a manufacturer-specific powertrain diagnostic trouble code recorded for Acura vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1133 is stored, the module has detected 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.

P1133 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 front heated oxygen sensor on bank 1 (Sensor 1) measures oxygen content in the exhaust and feeds the Engine Control Module (ECM) a switching voltage that the ECM uses to trim fuel delivery in closed loop. A properly working narrow band sensor swings rapidly between roughly 0.1V (lean) and 0.9V (rich), crossing the 0.45V midpoint several times per second at steady throttle. DTC P1133 sets when the ECM detects that this sensor is switching too slowly, or remains biased toward rich or lean for too long, over a calibrated period during closed loop operation. The driver may notice slightly incr...

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