Considering a bypass of your Cummins Signature engine's emissions system? A “delete,” typically referring to the removal of Diesel Particulate Filters (DPFs) and Selective Catalytic Reduction (SCR) systems , https://tools-directory.com/listings1260930/cummins-isx-modification-guide-everything-you-need-to-know-to-cummins-isx-engine-options