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Mike Kelly
Mike Kelly, Auto Mechanic
Category: Car
Satisfied Customers: 5469
Experience:  17 years experience as a auto mechanic,foreign and domestic.5 years running my own repair business.
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WHAT DOES CODE PO431 WARM UP CATALYST BELOW THRESHOLD BANK

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WHAT DOES CODE PO431 WARM UP CATALYST BELOW THRESHOLD BANK 2 ON A 2003 KIA SEDONA MEAN

Hi,how are you?The o2 sensors and the mass air flow sensor will make this code get stored in the system.The o2 sensor that you have not replaced is most likely what is making this code store.But also i would suggest checking out the mass air flow sensor.

 

 

 

 

Operation

 

The MAF is measured by detection of heat transfer from a hot film probe because the change of the mass air flow rate causes change in the amount of heat being transferred from the hot film probe surface to the air flow. The air flow sensor generates a pulse so it repeatedly opens and closes between the voltages supplied from the PCM. This results in a change of the temperature of the hot film probe and in the change of resistance.

Location

 

This sensor is located in the air intake plenum assembly. This sensor is combined with the IAT sensor.

Removal & Installation

 

  1. Disconnect the negative battery cable.
  2. Disconnect the connector from the sensor.
  3. Remove the air cleaner and air intake assembly, as required.
  4. Remove the sensor from its mounting.

 

To install:

  1. Installation is the reverse of the removal procedure.

 

Testing



2002-2005

  1. Run the engine until it reaches operating temperature.
  2. Using a voltmeter check the sensor output voltage.
  3. Specification should be as follows:

    Air mass 7.30 kg/h, output voltage 0.3 volt Air mass 10.06 kg/h, output voltage 0.5 volt Air mass 19.85 kg/h, output voltage 1.0 volt Air mass 35.58 kg/h, output voltage 1.50 volts Air mass 58.79 kg/h, output voltage 2.0 volts Air mass 94.70 kg/h, output voltage 2.5 volts Air mass 149.07 kg/h, output voltage 3.0 volts Air mass 226.66 kg/h, output voltage 3.5 volts Air mass 335.66 kg/h, output voltage 4.0 volts Air mass 500.16 kg/h, output voltage 4.5 volts Air mass 614.61 kg/h, output voltage 4.76 volts Air mass 730.01 kg/h, output voltage 5.0 volts
  4. If not within specification, replace the sensor.

 

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