Additional Symptoms Tests: Surges/Chuggles

WARNING: This page is about a different variant/trim than selected.

Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to Throttle Body Assembly Replacement .
Test the heated oxygen sensors (HO2S). The HO2S should respond quickly to a change in throttle position. If the HO2S do not respond to different throttle positions, inspect for contamination from fuel, silicon, or the incorrect use of RTV sealant. The sensors may have a white powdery coating and result in a high, but false, signal voltage, which gives a rich exhaust indication. The ECM reduces the amount of fuel delivered to the engine, causing a driveability condition.
Verify that each injector harness is connected to the correct injector.

IMPORTANT: A vehicle with a camshaft actuator uncontrolled and wandering may experience an engine surge.

Start and run the vehicle until fully warm. Observe the CMP variation parameter while accelerating up to 1,500 RPM and back to idle several times. The CMP variation should indicate a value for 1-2 seconds, then return to 0 degree. If the camshaft actuator does not respond, refer to Camshaft Position Actuator Cleaning and Inspection and Camshaft Position Actuator Magnet Cleaning and Inspection .