用读码器读一下FF(,FROZN FRAM). 里面有更多信息。我的tacoma也有这个码，reset后暂时还没出来。我查过，

Code P0420 indicates that the Bank 1 Catalyst System efficiency was below threshold for a predetermined period of time.

This condition will prevent the vehicle from running at its optimum efficiency and fuel economy may suffer.

Sensors indicate the catalytic converter is not reducing exhaust gas emissions properly.

 

 

OSC value smaller than standard value under active air-fuel ratio control (2 trip detection logic)

Possible Causes:

Front exhaust pipe Gas leakage from exhaust system

Air-Fuel Ratio (A/F) sensor (sensor 1)

Heated Oxygen (HO2) sensor (sensor 2)