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DPF regen too often

WLSchmett

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2019 Ram 3500 Laramie. I'm currently having to do a regen every 3 or 4 days. Light driving about 10 miles from work. Been to the shops once already. All they did was check it found no issues, changed to fuel filtersand the air filter and sent me on the way. Put a new S&B cold air intake one 2 days ago hoping it was just an airflow problem. Not the case. Just had to do another one today. Any suggestions?
 

thecastle

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Yeah I see the same behavior on mine when doing lots of idling, and just commuting with the vehicle on 10-15 mile drives. I have a 2019 3500 HO. There are two types of DPF regens, passive where exhaust temperatures are high enough for a sustained period to burn off PM (particulate matter); and the engine PM output is low enough to not out run the DPF passive regen. Then there is active regens for when the DPF gets loaded with PM and the exhaust is never hot enough to burn off the PM effectively. Cummins active regens then do diesel post injection events to dump unburnt fuel into the DOC (diesel oxidative catalyst) which combusts the fuel and heats the DPF to a high enough temp to regen. Its also possible your drives are too short for an active regen to complete successfully, so the system keeps trying over and over again to complete a regen. A longer highway drive occasionally should help. Increasing Air flow on a diesel lowers Exhaust Gas Temps (EGT), they work opposite of gasoline engines. Lowering EGT makes a passive DPF regen even more unlikely.

When I'm towing I never go through an active regen, my DPF gauge sits at 0% the whole time. Its just short trips unloaded and lots of idling where I see my DPF plugged gauge steadily rising and have to have an active regen.
 
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thecastle

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P.S. Having higher Cetane fuel also helps. The higher the Cetane rating of the diesel the easier and more completely it burns thus also lowering the chance of PM formation. The minimum nationwide is 40, and in non-attainment areas its often 48. If your "lucky" to live in California there is a chain of propel fuels stations that sell diesel HPR that have a cetane rating of 75.
 

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