Dtc P0420 Catalyst System Efficiency Below Threshold - Suzuki Jimny Service Manual

6-88 ENGINE GENERAL INFORMATION AND DIAGNOSIS

DTC P0420 Catalyst System Efficiency below Threshold

CIRCUIT DESCRIPTION
1. Heated oxygen sensor-1
2. Warm up three way catalytic
converter
NOTE:
For TYPE A and TYPE B, refer to the NOTE in "ECM Terminal Voltage Values Table" for applicable
model.
ECM monitors oxygen concentration in the exhaust gas which has passed the three way catalytic converter by
HO2S-2.
When the catalyst is functioning properly, the variation cycle of HO2S-2 output voltage (oxygen concentration) is
slower than that of HO2S-1 output voltage because of the amount of oxygen in the exhaust gas which has been
stored in the catalyst.
REFERENCE
1. Engine running at closed loop
condition
3. Three way catalytic converter
4. Heated oxygen sensor-2
2. Fuel cut
5. To the sensor
[A] : Case of TYPE A is shown
(See NOTE)
3. Idle after fuel cut
[B] : Case of TYPE B is shown
(See NOTE)
[A] : Oscilloscope waveforms