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:
On–vehicle inspection
1. Inspect cooling system for leaks
Caution:
to avoid the danger of being burned, do not remove the radiator
cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
fill the radiator with coolant and attach a radiator cap tester.
...
How to proceed with troubleshooting
The hand–held tester can be used at step 3, 4, 5, 7, 10.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Connect hand–held tester to dlc3
Hint:
if the display indicates a communication fault in the tool, inspect dlc3.
4 Check dtc and freeze frame data
Hint:
record or pr ...
Inspection procedure
Hand–held tester:
1 Perform active test by hand–held tester(operation of circuit
opening relay)
Connect the hand–held tester to the dlc3.
turn the ignition switch on and push the hand–held tester main
switch on.
select the item ”diagnosis / enhanced obd ii / active ...