Diagnostic Trouble Code (DTC) Information

ECM-4801 THREE-WAY CATALYTIC CONVERTER (TWC) EFFICIENCY
DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION




Condition
The Control module continuously checks three-way catalytic converter (TWC) effectiveness by comparing signals from the rear heated oxygen sensor (HO2S) with the front heated oxygen sensor (HO2S). Diagnostic trouble code (DTC) ECM-480 1 will be stored if the efficiency of the three-way catalytic converter (TWC) deviates too much.

Condition
Rear heated oxygen sensor (HO2S) is disabled.

Possible source
- misfiring
- air leakage in the intake system
- air leakage in the exhaust system
- faulty fuel pressure
- uneven compression
- defective three-way catalytic converter (TWC)

Condition
- malfunction indicator lamp (MIL) lit