Reviewed By matthew h (GRAND COULEE, WA) Reviewed for a 2011 GMC Sierra —12/19/2014 5:26 AM
Range product works well. It was easy to install. The AFM was causing my truck to "learch" when stopped at slow speeds (engine shifting from 8 to 4 cyclinders). Also had a lot of burnt oil leaving black residue near the tailpipe. The common problems you see with the GMC FLEX Fuel design. This product fixed them all. I did loose 2 mpg 19to17. More instant power overall. Good product to purchase if you decide to keep the truck instead of sell or return for one without the AFM issues.