P0420 LEXUS Catalyst System Efficiency Below Threshold Bank 1

Possible causes – Three way catalyst converter Bank 1– Exhaust tube– Intake air leaks– Fuel injectors may be faulty– Fuel injector leaks– Spark plugs may be faulty– Improper ignition timing– Engine Control Module (ECM) Tech description As the code description implies the P0420 code means that the vehicle’s control module has detected that the three-way…