Possible causes

– Faulty HO2S Bank 1 Sensor 1
– HO2S Bank 1 Sensor 1 harness is open or shorted
– HO2S Bank 1 Sensor 1 circuit poor electrical connection

When is the code detected?

The P1134 is sets if the Powertrain Control Module (PCM) detects the HO2S ratio is not within range.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1134 CADILLAC Description

The Powertrain Control Module (PCM) monitors the Heated Oxygen Sensor (HO2S) activity. During the monitor period the PCM counts the number of times that the HO2S responds from rich to lean and from lean to rich and adds the amount of time it took to complete all transitions. With this information, an average time for all transitions can be determined. The PCM then divides the rich to lean average by the lean to rich average to obtain a ratio.