I have a 2013 Chevy Malibu 75K miles and the engine power reduced light came on along with the engine light, stability light, and traction light. Mechanic said diagnostic gave code for bad fuel pump so I had it replaced for $475. Nothing changed after the installation of a new fuel pump. Then the mechanic said air mass flow sensor was bad so I got that replaced and still no improvement. I stopped trusting the mechanic and took it to my cousin who said he thought it was the high pressure fuel pump which is located inside the engine. Boom! Car fixed. Hope this helps someone. If your 2013 malibu is showing bad fuel pump make sure you have the right one replaced if possible!