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:
Adjustment
1. Put vehicle these conditions
tire inflation pressure is the specified value .
start the engine.
2. Adjust fog light aim
The fog light aim can be adjusting by moving the aiming
screw in the vertical direction.
Hint:
the optical aim moves upward when turning a scr ...
On–vehicle inspection
1. Inspection throttle body idle speed control valve assy
Notice:
it is impossible to check the resister value and the operation
of isc valve by itself, because the isc valve
has an ic circuit inside it, which transforms the duty
signal from the ecm to the derive signal.
After check ...
Circuit description
A flat type knock sensor (non–resonant type) has the structure that can
detect the vibration in a wider band
of frequency from about 6 khz to 15 khz and has the following features.
Knock sensors are fitted on the cylinder block to detect the engine knocking.
The sensor contains a piezoele ...