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:
Replacement
1. Work for preventing gasoline from spilling out
2. Remove engine under cover rh
3. Drain coolant
4. Remove front wheel rh
5. Remove cylinder head cover no.2
Remove the 2 nuts, 2 clips and cylinder head cover.
6. Remove air cleaner hose no.1
loosen the 2 air cleaner hose ...
Inspection procedure
1 Check ignition or starter switch assy
Check the ignition switch, as shown in the illustration and
table.
Standard:
2 Check fuse (ecu–b)
Remove the fuse from the instrument panel j/b.
check the continuity of the fuse.
Standard: continuity
3 Check relay (m ...
Circuit description
The camshaft position sensor (g22+ signal) consists of a magnet, iron core
and pickup coil.
The g22+ signal plate has 3 teeth on its outer circumference and is installed on
the camshaft timing pulley.
When the camshafts rotate, the protrusion on the signal plate and the air gap on
the pi ...


