The blocker plates can get confusing for why to install them and how many do you need to install. So to clear this up! As the manufacture of the Toyota bypass kit we advise installing the plates no matter what AIP CEL codes your vehicle is receiving. Also each kit has two Blocker plates that come with the Bypass Module, both the plates need to be installed. This does not matter if you have a 4.7L and a 5.7L engine, The confusion is that the 4.7L has one pump and the 5.7L has two pumps but regardless how many pumps, your vehicle has two exhaust ports that need to be blocked when installing the Toyota bypass kit.