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:
Parking brake
Operating instructions
1 To set the parking brake, fully pull the parking brake lever while depressing
the brake pedal.
2 To release the parking brake, slightly raise the lever and lower it completely
while pressing the button.
*1: For U.S.A.
*2: For Canada
■Parking brake engaged wa ...
Problem symptoms table
Hint:
if a normal code is displayed during the dtc check but the trouble still occurs,
check the circuits for each
symptom in the order given in the charts on the following pages and proceed to
the page given for troubleshooting.
The matrix chart is divided into 3 chapters.
If the instruc ...
Circuit description
The intake air temperature (iat) sensor, mounted on the mass
air flow (maf) sensor, monitors the intake air temperature. The
iat sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermisto ...