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 d squib circuit(airbag sensor assy center – horn button
assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the horn button assy.
release the airbag activ ...
Inspection procedure
Hint:
if different dtcs related to different systems that have terminal e2
as the ground terminal are output
simultaneously, terminal e2 may be open.
Read freeze frame data using the hand-held tester or the obd ii scan
tool. Freeze frame data records
the engine conditions when a malf ...
Repair
1. Steering off center repair procedure
Inspect steering wheel off center.
Apply masking tape on the top center of the steering
wheel and steering column upper cover.
Driving the vehicle on a straight line for 100 meters
at a constant speed of 35 mph (56 km/h), and ho ...