Rough Idle

Check in Order Listed:

^ Engine Control Module
Check Malfunction Indicator Light (MIL) action (see Diagnostic Trouble Code Extraction). Is MIL coming on/are codes stored/is light on steady?

^ Idle Control System
Inspect all hoses and connections.

^ Idle Air Control Valve (IAC)
Perform IAC Valve tests as shown for Diagnostic Trouble Code (DTC) 14.

^ Emission Control System
Positive Crankcase (PCV) Ventilation System - Perform test of PCV System.

^ Fuel Supply System
Fuel Injector - Perform Fuel Injector test as shown for DTC 16.
Injector Resistor - Perform test of Injector Resistor.
Contaminated Fuel - Inspect for contaminated fuel.

^ Manifold Absolute Pressure (MAP) Sensor
Perform Manifold Absolute Pressure Sensor tests as shown for DTC 3 & 5.