Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Catalyst system efficiency below
threshold
Toyota Corolla (E120): Catalyst system efficiency below threshold
Dtc p0420 catalyst system efficiency below threshold (bank 1)
Other materials:
Circuit description
A thermistor is built in the engine coolant temperature sensor and changes
the resistance value according
to the engine coolant temperature.
The structure of the sensor and connection to the ecm is the same as those of
the intake air temperature
sensor.
Hint:
if the ecm detects the dtc ...
Inspection
1. Intake air flow meter sub–assy
Inspect the intake air flow meter resistance.
Using an ohmmeter, measure the resistance between
terminals tha and e2.
Resistance:
at –20 c (–4 f) 13.6 To 18.4 KΩ
at 20 c (68 f) 2.21 To 2.69 KΩ
at 60 c (140 f) 0.49 To 0.67 ...
USB charging port (if
equipped)
The USB charging port are used
to supply 3.0 A of electricity at 5
V to external devices.
The USB charging port are for
charging only. They are not
designed for data transfer or
other purposes.
Depending on the external
device, it may not charge properly.
Refer to the manual
included with the dev ...