Lotus Evora - Catalyst System Efficiency

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Lotus Service Notes Section EMR
Catalyst System Efficiency
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0430 Catalyst System Efficiency Below Threshold (Bank 2)
Description
The ECU compares the waveform of the oxygen sensors located before and after the catalyst to determine
whether or not the catalyst has deteriorated. If the catalyst is functioning normally the front oxygen sensor will
be switching between rich and lean whilst the rear oxygen sensor should also be switching between rich and
lean but more slowly. When both the oxygen sensor waveforms change at a similar rate, it indicates that the
catalyst performance has deteriorated. The ECU counts the number of pre and post catalyst oxygen sensor
switches and divides one by the other to determine a ratio. If this ratio is too high a fault will be indicated.
Sensor connections
Pre catalyst oxygen sensor
Sensor Connector Description ECU Pin ECU Connector
1 Bank 1 Signal G3 48 Way (Centre)
2 Bank 1 Ground J2 48 Way (Centre)
3 Bank 1 Heater Supply H3 48 Way (Centre)
4 Bank 1 Battery Voltage - -
1 Bank 2 Signal G4 48 Way (Centre)
2 Bank 2 Ground J2 48 Way (Centre)
3 Bank 2 Heater Supply H4 48 Way (Centre)
4 Bank 2 Battery Voltage - -
Post catalyst oxygen sensor
Sensor Connector Description ECU Pin ECU Connector
1 Bank 1 Signal H1 48 Way (Centre)
2 Bank 1 Ground K4 48 Way (Centre)
3 Bank 1 Heater Supply K1 48 Way (Centre)
4 Bank 1 Battery Voltage - -
1 Bank 2 Signal H2 48 Way (Centre)
2 Bank 2 Ground K4 48 Way (Centre)
3 Bank 2 Heater Supply K2 48 Way (Centre)
4 Bank 2 Battery Voltage - -
Monitor:
• Continuous
Enable Criteria:
• Closedloopfuelcontrolenabled
• Coolanttemperature>60°C(140°F)
• Baro>756mbar
• Vehiclespeed<130km/h(81mph)
• MAF<48g/sec&MAF>2g/sec
• Airinlettemp>-10°C(14°F)
• AccumulatedMassAir>2000-4080gramsdependingoncoolanttemperature
2009/02