Volvo DPF Pressure

[TruckDoctor]

Keep in mind unlike Cummins, Volvo doesn't check pressure after the DPF Outlet, nor do they have a exhaust pressure sensor like a Cummins. If you plumbed a pressure gauge to the inlet "DOC" section of the DPF (usually a 1/8 pipe plug fitting) you are checking complete Exhaust System Back Pressure. Being a US10 emissions truck with DEF and SCR system you could have a clogged SCR inlet pipe, or SCR Catalyst causing overall high exhaust system back pressure. Being there is only a differential pressure sensor on the DPF it could have 1.4 psi on the inlet and say 1.2 psi on the outlet side which is still going to make your differential pressure sensor seem to be "in spec" doesn't mean overall system back-pressure is to high. 1.4 psi at high RPM doesn't sound crazy through the moon. I've seen worse. Is the truck asking for regen's all the time? Also if you were to map a US10 emission Volvo with a laptop it quickly will get to around 100% soot load and its not an issues. Those trucks will do active passive regen's sometimes up in the 130% range. 100% on the dash usually doesn't even ask for a forced parked regen yet. US10 D11 Volvo can regen up to 200% soot load before needing a maintenance reset. I'd make sure have someone regen it with laptop and make sure you have roughly 55k-65k for turbo speed and T2 and T3 temperatures between 850-910 degrees. US07 trucks were hotter and they brought the temps down for a few years. Now US17 trucks are back up regening around 1100 degrees during what they now call a "sulfur regen"