Except California Emission Regulation Applicable ATX Model

DTC P0133 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0133	Front HO2S circuit problem
DETECTION CONDITION	Oxygen sensor malfunction is detected by measuring of the average frequency of oxygen sensor signal, time required to pass from rich to lean, time required to pass from lean to rich. The average frequency of oxygen sensor signal is more than the threshold value. MONITORING CONDITIONS HO2S heater, HO2S, and TWC Repair Verification Drive Mode Following conditions are met: Front HO2S heater monitor is completed. Fuel system loop status is closed loop fuel control. ECT sensor and front HO2S heater and normal. Engine speed: 1, 500-3, 500 RPM Charging efficiency: 15-63 % (at engine speed is 2, 500 RPM) Engine coolant temperature above 70 °C {158 °F} Diagnostic support note This is an intermittent monitor. (HO2S) The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. DIAGNOSTIC MONITORING TEST RESULTS is available. PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. FREEZE FRAME DATA is available. DTC is stored in the PCM memory.
POSSIBLE CAUSE	Front HO2S deterioration Front HO2S malfunction Front HO2S looseness Fuel pump malfunction Fuel pressure regulation malfunction Clogged or restricted fuel filter (built-in fuel pump unit) Fuel leakage in fuel line between fuel distribution pipe and fuel pump Exhaust system leakage Purge solenoid valve malfunction Improper connection purge solenoid hose Insufficient compression Engine malfunction (Engine coolant leakage)

DTC P0133

Front HO2S circuit problem

DETECTION CONDITION

Oxygen sensor malfunction is detected by measuring of the average frequency of oxygen sensor signal, time required to pass from rich to lean, time required to pass from lean to rich.
The average frequency of oxygen sensor signal is more than the threshold value.
MONITORING CONDITIONS
- HO2S heater, HO2S, and TWC Repair Verification Drive Mode
- Following conditions are met:
  - Front HO2S heater monitor is completed.
  - Fuel system loop status is closed loop fuel control.
- ECT sensor and front HO2S heater and normal.
- Engine speed: 1, 500-3, 500 RPM
- Charging efficiency: 15-63 % (at engine speed is 2, 500 RPM)
- Engine coolant temperature above 70 °C {158 °F}

Diagnostic support note

This is an intermittent monitor. (HO2S)
The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
DIAGNOSTIC MONITORING TEST RESULTS is available.
PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.
FREEZE FRAME DATA is available.
DTC is stored in the PCM memory.

POSSIBLE CAUSE

Front HO2S deterioration
Front HO2S malfunction
Front HO2S looseness
Fuel pump malfunction
Fuel pressure regulation malfunction
Clogged or restricted fuel filter (built-in fuel pump unit)
Fuel leakage in fuel line between fuel distribution pipe and fuel pump
Exhaust system leakage
Purge solenoid valve malfunction
Improper connection purge solenoid hose
Insufficient compression
Engine malfunction (Engine coolant leakage)