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:
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 feedback compensation keeps the waveform of the heated oxygen
sensor in front of the catalyst
alterna ...
Tape is tangled due to incorrect tape speed or
auto–reverse malfunction
Inspection procedure
1 Check for any foreign object
Check for any foreign object.
Check that no foreign material and troubles are detected in the radio
receiver assembly cassette
tape player.
Standard: no foreign material and trouble detected.
2 Replace cassette tape with an ...
Parking brake
The parking brake can be
set or released automatically
or manually.
In automatic mode, the
parking brake can be set or
released automatically
according to shift lever
operation.
Also, even in automatic
mode, the parking brake can
be set or released manually.
Operating instructions
■ Using the ma ...