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
Refer to dtc p0130
Dtc no.
Dtc detecting condition
Trouble area
P0134
After engine is warmed up, heated oxygen sensor (bank 1
sensor 1) output does not indicate rich (greater than 0.45 V)
even once when conditions (a), (b), (c), (d) and (e) continue for
...
Wireless remote control/electronic key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
● Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2016 (vehicles without a smart key system), or CR2032 (vehicles
with a smart key system)
Replacing the battery
...
Monitor description
The battery supplies electricity to the ecm even when the ignition switch is
off. This electricity allows the
ecm store data such as dtc history, freeze frame data, fuel trim values, and
other data. If the battery voltage
falls below a minimum level, the ecm will conclude that there is a fault ...


