Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

DTC P3401, P3425, P3441, and P3449 are type B DTCs.
The engine will return to V8 mode.
The fuel injector will turn OFF for the cylinder that has a cylinder deactivation DTC set, resulting in an engine misfire.