MISHIMOTO PERFORMANCE INTERCOOLER 17-19 GM 6.6L L5P DURAMAXBuilt to handle heavy payloads, provide impressive performance, and execute years of reliable service, the 2017 2019 6. 6L Duramax L5P is an absolute workhorse. However, as with any factory vehicle, some systems have limitations and areas that can be improved. Mishimoto's engineering team has specifically identified the L5P's intercooler system as one of these areas. As a result, they've developed a performance intercooler kit for the 2017 2019