For any number of reasons, performance enthusiasts working with select LS and all of the new Gen V LT engines may want to delete the Active Fuel Management (AFM) system, also called Displacement on Demand (DOD). One of the key steps in that operation is plugging the oil-flow passages in the cylinder block that feed the system.
“If you do not, you may have significant internal oil leaks that can result in problems with low oil pressure,” says Jason Haines of Lingenfelter Performance Engineering.
Read More: http://www.lsxmag.com/news/tech-quickie-plugging-ls-blocks-to-delete-afmdod/