Toyota Corolla Repair Manual: Catalyst system efficiency below threshold
Dtc p0420 catalyst system efficiency below threshold (bank 1)
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
usefu ...
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 feedba ...
Other materials:
Follow the correction procedures. (vehicles with a smart key system and with
a drive monitor display)
After taking the specified steps to correct the suspected problem, check that
the warning light turns off.
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact
sensors, side impact sensors (front door), side impact sensors (front), side impac ...
Fuel
Preparation
Sst
Recomended tools
Ssm
Equipment
...
Thermostat
Replacement
1. Remove engine under cover rh
2. Drain coolant
3. Remove fan and generator v belt
4. Remove generator assy
Disconnect the wire clamp from the wire clip on the rectifire
end frame.
remove the rubber cap and nut, and disconnect the alternator
wire.
d ...