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
When a misfire occurs in the engine, hydrocarbons (hc) enter the exhaust in
high concentrations. If this hc
concentration is high enough, there could be an increase in exhaust emissions
levels. High concentrations
of hc passing through the catalyst also cause to temperature of the catalyst to ...
Inspection procedure
1 Inspect stop lamp switch assy
Check that the stop light lights up when brake pedal is depressed and
turns off when the brake pedal
is released.
2 Inspect skid control ecu terminal voltage(stp terminal)
Disconnect skid control ecu connector.
measure voltage between termina ...
Speed control main switch assy
Replacement
1. Disconnect battery negative terminal
2. Inspect place front wheels facing straight ahead
3. Remove horn button assy
4. Remove steering wheel assy
sst 09950–50013 (09951–05010, 09952–05010, 09953–05020, 09954–05021)
5. Remove speed control main switch assy
Remov ...