Code Definition

P1134 — HO2S Transition Time Ratio Sensor 1

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

About P1134

P1134 is a manufacturer-specific powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1134 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.

P1134 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

This code sets when the powertrain control module (PCM) detects that the upstream heated oxygen sensor (HO2S) is not switching between rich and lean conditions at the expected rate. The transition time ratio refers to the sensor’s ability to respond quickly to changes in the air-fuel mixture. A slow response can lead to inefficient fuel control and increased emissions.

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