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:
Inspection procedure
1 Check relay (marking: starter cut)
Inspect the relay continuity, as shown in the illustration
and table.
Standard:
2 Check tvip ecu
Disconnect the tvip ecu connector.
turn the ignition switch position to the start.
measure the voltage between the termina ...
Disabling the TRAC system
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may reduce power
from the engine to the wheels. Pressing
to turn the system off may make it
easier for you to rock the vehicle in order to free it.
To turn the TRAC system off, quickly press and release
.
The “TRAC OFF” ind ...
Circuit description
The rear heated oxygen sensor is used to monitor oxygen concentration in the
exhaust gas. For optimum
catalytic converter operation, the air fuel mixture must be maintained near the
ideal ”stoichiometric” ratio.
The heated oxygen sensor output voltage changes suddenly in the vicinity of ...