DTC P0134: Ho2S (Front) Circuit, No Activity Detected: Condition

DTC is set when front HO2S signal voltage does not exceed .55 volt for 120 seconds after engine coolant temperature has reached more than 158°F (70°C) and engine speed is more than 1500 RPM. PCM monitoring is performed during Drive Mode 3 - HO2S, HO2S heater & TWC repair verification. See DRIVE MODES  under SELF-DIAGNOSTIC SYSTEM. This is a continuous monitor. MIL is illuminated when PCM detects malfunction during 2 consecutive drive cycles. Possible causes are:

• Engine malfunction.
• Exhaust system leak.
• Front HO2S deterioration or malfunction.
• Low engine compression.
• Open or short circuit between front HO2S and PCM.