Hesitation, Sag, Stumble

Test the fuel pressure. Refer to Fuel System Diagnosis .
Test the manifold absolute pressure (MAP) sensor. Refer to DTC P0106 .
Test the generator. Refer to Symptoms - Engine Electrical . Repair the charging system if the generator output voltage is less than 9 V or more than 16 V.
Engine warm and idling, verify the correct operation of the camshaft actuator system. Command the intake and exhaust camshaft actuators from 0 degrees to 20 degrees and back to zero while observing the scan tool Intake Camshaft Position Variance and Exhaust Camshaft Position Variance parameters. Each parameter should be less than 2 degrees in each of the commanded states.
NOTE: The following actions may need to be repeated in order to verify an intermittent intake or exhaust camshaft actuator condition.
- If any of the parameters is greater than 2 degrees, inspect the suspect camshaft actuator and camshaft actuator solenoid valve and valve bore for contamination, obstruction and damage. Refer to Camshaft Actuator System Description and Camshaft Position Actuator Solenoid Valve Replacement .