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:
Brake
On–vehicle inspection
1. Inspect brake line pipes and hoses
Hint:
work in a well–lighted area. Turn the front wheels fully to the
right or left before begining.
check all the brake lines and hoses for:
damage
wear
deformation
cracks
corrosion
leaks
bends
twi ...
Rear view monitor system precautions
■ Area displayed on screen
The rear view monitor system displays an image of the view from the bumper of
the rear area of the vehicle.
To adjust the image on the rear view monitor system screen.
• The area displayed on the screen may vary according to vehicle orientation
conditions.
...
Circuit description
The ecm compares the two waveforms of the heated oxygen sensors located
before and after the catalyst
to determine whether or not the catalyst performance has deteriorated.
Air–fuel ratio feedback compensation keeps the waveform of the heated oxygen
sensor in front of the catalyst
alterna ...