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Home >> Lexus >> 2010 >> RX 350 FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control (Diagnostic Codes (P0340-P0606) >> SFI System >> DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) (2010 To 08/2009) >> Conditioning For Sensor Testing
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Conditioning For Sensor Testing

HINT: 

Perform the operation with the engine speeds and time durations described below prior to checking the waveformsFig 2 of the air fuel ratio and heated oxygen sensors. This is in order to activate the sensors sufficiently to obtain the appropriate inspection results.

Fig 1: Confirmation Driving Pattern
GTY255786Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. Connect the Techstream to the DLC3 [A].
  2. Start the engine and warm it up with all the accessories switched off, until the engine coolant temperature stabilizes [B].
  3. Run the engine at an engine speed of between 2500 rpm and 3000 rpm for at least 3 minutes [C].
  4. While running the engine at 3000 rpm and 2000 rpm for 2 seconds, check the waveformsFig 2 of the air fuel ratio and heated oxygen sensors using the Techstream [D].

    HINT: 

    • If either of the voltage outputs of the air fuel ratio or heated oxygen sensor does not fluctuate, or either of the sensors makes a noise, the sensor may be malfunctioning.
    • If the voltage outputs of both the sensors remain lean or rich, the air fuel ratio may be extremely lean or rich. In such cases, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor.
    • If the three-way catalytic converter has deteriorated, the heated oxygen sensor (located behind the three-way catalytic converter) voltage output fluctuates up and down frequently, even under normal driving conditions (active air fuel ratio control is not performed).
Fig 2: Air Fuel Ratio Sensor Output Voltage Graph
GTY288418Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002