Engine Hood Courtesy Switch
Parts LocationCatalyst System Efficiency Below Threshold (Bank 1) (P0420)
MONITOR DESCRIPTION
The ECM uses sensors mounted in front of and behind the Three-Way Catalytic Converter
(TWC) to monitor its efficiency.
The first sensor, the air fuel ratio sensor, sends pre-catalyst information to
the ECM. The second sensor, the heat ...
Inspection
INSPECTION
PROCEDURE
1. INSPECT ATF TEMPERATURE SENSOR ASSEMBLY
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Sp ...
Precaution
PRECAUTION
1. PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL
NOTICE:
When disconnecting the cable from the negative (-) battery terminal, initialize
the following system after the terminal is reconnected:
System Name
...