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:
Hood
Release the lock from the inside of the vehicle to open the hood.
1 Pull the hood lock release lever.
The hood will pop up slightly.
2 Pull up the auxiliary catch lever and lift the hood.
3 Hold the hood open by inserting the support rod into the slot.
CAUTION
■Pre-driving check
C ...
Overhaul
1. Remove oil filler cap sub–assy
Remove the oil filler cap from the cylinder head cover.
2. Remove oil filler cap gasket
Using a screwdriver, remove the gasket from the oil filler
cap.
3. Remove ventilation valve sub–assy
Remove the ventilation valve from the cyl ...
How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Warning light check
4 The dtcs check (present and past dtcs)
5 The dtcs chart
6 Circuit inspection
7 Repair
8 Clear the dtcs (present and past dtcs)
9 The dt ...