Review on K&N Cold Air Intake Kit for 2004-2006 Chevy/GMC/Hummer (Colorado, Canyon, H3) 3.5L L5 - High Performance, Increased Horsepower, 50-State Legal (Part Number: 57-3043) by Christopher Ruth

There is no doubt that this is a high-quality product. However, adding it to the 2006 Hummer H3 caused a lot of problems; Jacked up the DMRV, the electronic pedal doesn't know how to boost the octane, and the list goes on. If I wasn't a mechanic and couldn't diagnose problems I would sell it or take the loss and put the original system back on the Hummer. I am very happy that everything has worked out now. Be aware that you will run into some issues if you install this on your old rig. Just be prepared. love it now! (By the way, I don't see any difference with MPG)