Hey gang I'm new today and have an issue. My sisters 2008 grand prix has a shut down issue. Message center displays "Reduced Engine Power" then very briefly displays "Electronic Throttle Control". Local dealership instructed to replace Secondary Air Injection Pump, the Air Injection Pump, and Electronic Throttle Assembly. Replaced all three in series each time problem remained, even after hard codes were erased. Code on ODB scan tool is 411. Shut down minutes after start still occurs. Any solutions that you may have to offer?