DTC P1134 & P1154: Ho2S Transition Time Ratio - Bank 1 & 2, Sensor 1: Description
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The Powertrain Control Module (PCM) monitors the Heated Oxygen Sensor (HO2S) activity. During the monitoring period, the PCM counts the number of times that the HO2S responds from rich to lean, and from lean to rich. The PCM adds the amount of time that was necessary to complete all the transitions. With this information, the PCM can determine an average time for all transitions. The PCM then divides the rich to lean average by the lean to rich average in order to obtain a ratio. A DTC P1134 or P1154 sets if the HO2S ratio is not within the range.