Dtc P0420: Catalyst System Efficiency Below Threshold - Suzuki Swift Sport 2004 Service & Repair Manual

1A-120 Engine General Information and Diagnosis:

DTC P0420: Catalyst System Efficiency below Threshold

System and Wiring Diagram
BLU WHT
1
3
1. HO2S-1
2. HO2S-2
Circuit Description
ECM monitors oxygen concentration in the exhaust gas which has passed the warm up 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 warm up three way catalytic converter.
Reference
YEL
WHT BLU
2
3. Warm up three way catalytic converter
4. Three way catalytic converter
Oscilloscope waveforms
WHT C37-10
YEL C37-57
BRN C37-11
4
S7RS0B1104046
5
5 V
I4RS0A110037-01
5. ECM
I2RH01110102-01