What is a DOC

DOC is the Diesel Oxidation Catalyst. It effectively works as a giant glow plug in the exhaust in order to help burn off the remaining fuel that did not fully burn off in the combustion process.

What Does the DOC do?

Ultimately it’s responsible for removing many of the harmful combustion resultants by using heat and catalytic precious metals to solicit a chemical reaction. In doing so, it more completely burns off the exhaust gasses.

I mainly have issues with
my DPF, so why do I care?

Well remember above that we commented that the DOC helps to burn off the fuel more completely? Well soot (Diesel Particulates) are simply particles of fuel that did not fully burn off during the combustion process. Therefore, a fully and properly functioning DOC will actually significantly improve the service life of a DPF!

Get Your DOC at DPFparts.com Now!

So if you’ve been having endless issues with your DPF, the problem might not be the DPF at all!

If you keep experiencing issues with the DPF, the unfortunate reality is that you’ve probably not correctly diagnosed the root cause of the DPF build up, causing it to build up once again.


As always, if you need specific help, the guys from Diesel Laptops are awesome (jump on their train if you haven’t already).


If you need cleaning, talk to the friendly team DPF Cleaning / DCARB 877 573 2272.


If you’re looking for a new filter, check these guys out at DPFParts.com



The caterpillar engine dpf