Toyota Corolla (E120): Components
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 ...
Replacement
1. Disconnect battery negative terminal
2. Remove engine under cover rh
3. Remove starter assy
Disconnect the starter connector.
open the terminal cover.
remove the nut, then disconnect the starter wire.
remove the 2 bolts, then remove the starter.
4. Install starter a ...
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...