Rough, Unstable, or Incorrect Idle and Stalling
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect the engine mounts. Refer to Engine Mount Inspection .
- Inspect the intake and exhaust manifolds for casting flash.
- The exhaust system for damaged or collapsed pipes
- The exhaust manifold for a collapsed inner wall
- The mufflers for heat distress or possible internal failure
- EMI on the reference circuit can cause an engine miss condition. A scan tool can usually detect EMI by monitoring the engine RPM. A sudden increase in RPM, with little change in actual engine RPM change, indicates that EMI is present. If a problem exists, inspect routing of high voltage components, such as fuel injector wiring, near the sensor circuits.
- Inspect the park neutral position (PNP) switch circuit.