The LMM, also known as the “new body style” Duramax, was introduced mid-2007 and continued through 2010. To easily identify the 07.5-10 LMM motor the eighth digit in the vin number will be a “6”. The LMM was start of a new generation of emission compliance sanctioned by the EPA. This is where the diesel particulate filters (DPF) were introduced to greatly reduce soot and particulate matter. The LMM has updated programming to run clean and lean, updated to an even more efficient Variable Geometry Turbo (VGT), along with an upgraded Exhaust Gas Recirculation (EGR) System, plus many other emission centric “upgrades”.
With all the new sanctioned emission equipment added to these LMM motors came some downfalls. Most of the warranties used for these trucks pointed towards the emission equipment. It is very common for these DPF filters to get sooted up and no longer able to run through their standard regeneration cycle to clean them. This forces the filter to be professionally cleaned by the dealership or for them to be permanently removed. The EGR’s have the same issue, they tend to get clogged up, preventing airflow which increases overheating issues. In race applications, the exhaust will be removed and straight piped, the EGR will be removed or blocked off, and the computer will be tuned and reprogrammed to allow the truck to perform more efficiently and cooler.