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
Hint:
troubleshoot each trouble symptom in accordance with the chart below.
1 Clear dtc
Connect the hand–held tester or the obd ii scan tool to the dlc 3.
turn the ignition switch on and push the hand–held tester or the
obd ii scan tool main switch on.
read the dtc . ...
Check dlc3
The vehicle’s ecm uses the iso 9141–2 for communication
protocol. The terminal arrangement of the dlc3 complies
with sae j1962 and matches the iso 9141–2 format.
Hint:
if the display shows unable to connect to vehicle
when you have connected the cable of the obd ii scan tool or
the h ...
Automatic transaxle assy (atm)
Precaution
The automatic transaxle is composed of highly precision–finished
parts, necessitating careful
inspection before reassembly because even a small nick could cause fluid
leakage or affect
the performance. The instructions here are organized so that you work on
only o ...


