Code No. P0133: Right Bank Oxygen Sensor (front) Circuit Slow Response

OPERATION

• The sensor signal is inputted to the engine-ECU connector terminal O2FR from the right bank oxygen sensor (front) output terminal.
  
• The right bank oxygen sensor (front) is earthed with engine-ECU connector terminal O2VE.
  
• The engine-ECU connector terminal O2VE applies an offset voltage of 0.5 V to the right bank oxygen sensor (front).
  

FUNCTION

• The right bank oxygen sensor (front) converts the concentration of oxygen in the exhaust emission into a voltage and inputs the signal to the engine-ECU.
  
• When the air-fuel ratio is richer than the theoretical air-fuel ratio, the right bank oxygen sensor (front) outputs a voltage of about 1 V. When it is leaner than the theoretical air-fuel ratio, it outputs a voltage of about 0 V.
  
• In response to the signal, the engine-ECU controls the fuel injection amount so that the air-fuel ratio can be equivalent to the theoretical air-fuel ratio.
  

TROUBLE JUDGEMENT

• Engine coolant temperature is more than 60°C.
  
• Engine speed is more than 1,250 r/min and is less than 3,500 r/min.
  
• Volumetric efficiency is more than 25 % and is less than 65 %.
  
• Under the closed loop air/fuel control.
  
• The accelerator pedal is open.
  
• Short-term fuel trim is more than -25 % and is less than +25 %.
  
• More than 2 seconds have elapsed after the above mentioned conditions have been met.
  
• The engine-ECU monitors for this condition for 5 cycles of 12 seconds each during the drive cycle.
  

• The average of the right bank oxygen sensor (front) rich/lean switching frequency is less than 6 times per 12 seconds.
  

FAIL-SAFE AND BACKUP FUNCTION

• None
  

PROBABLE CAUSES

• Failed right bank oxygen sensor (front)
  
• Loose connector contact
  
• Failed engine-ECU
  

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Go to Step 2.

	Go to Step 3.

	Replace the right bank oxygen sensor (front).

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Replace the engine-ECU.