Removing DPF for DIY clean

[JimT]

(03-09-2020 )Jorg81 Wrote:  The way I saw was a guy on YouTube and he did it with just water with a pressure sprayer. He said his shop has been doing it this way with success. Maybe it's not the best though. It's hard to know, but it doesn't seem like water would be destructive.

It's hard to appreciate just how thin and fragile the material of the DPF/DOC really is until you've had to remove it from the metal can. There are a ceramic material that it about as thick as a piece of construction paper and is coated with an exceedingly thin (nearly microscopic) layer of platinum (and maybe other metals). Lets just say it makes aluminum foil look like thick armor. Now think about the destructive force that is pressure washing. It can strip paint, clean concrete. High pressure water is also used to cut metals.

Even if you didn't touch the metal coated DOC, the DPF is made up of thousands of very small channels that zig zag through the metal can. They don't actually go straight through. So forcing water and soot through these channels at high pressures and velocities can cause it to punch through the other side, or more commonly, get stuck and clog up the passageway with a carbon mud. Then, ANY moisture still trapped inside can quickly boil and turn to steam from even low exhaust temps, causing rapid internal expansion and cracking. Once that happens it's about as useful as a boat anchor.

Finally, there is a very important reason why you want to flow test the DOC and DPF after cleaning. If the restriction is too high when clean (I think either 3psi or 3inHg or more) then it is considered to be no good and needs to be replaced.

So, by all means, remove the DOC/DPF yourself, save some labor costs and learn more about your equipment. But don't try to clean them yourself, you're just asking for trouble and a huge replacement cost.