P0133 - HO2S Circuit Slow Response (Bank 1, Sensor 1)

The HO2S-11 circuit is monitored by the Powertrain Control Module (PCM). The test fails when the HO2S-11 signal cycling time is more than the specified time.

Possible Causes:
^ HO2S-11 circuit is open
^ HO2S-11 circuit is shorted to VPWR
^ HO2S-11 circuit is shorted to GND
^ Front HO2S
^ Front HO2S heater
^ Fuel pressure
^ Injectors
^ Intake air leaks
^ Exhaust gas leaks
^ PCV valve
^ Mass air flow (MAF) sensor

Diagnostic Aids:
The HO2S-11 change from rich to lean more than 5 times during 10 seconds with the engine running at 2,000 rpm.