CM871 High DOC temp during regen

[tariqzai]

(04-12-2020 )Rawze Wrote:  Take DOC and DPF to stealeras$it that has proper machine. Have Baked the DOC and DPF, de-ashed, and flow tested.

How old are DOC and DPF?. How many miles?

-- According to the pic of the temps, te DOC inlet is too high, and it loks exactly like when someone swaps around the DPF inlet and outlet temp sensors. - DOC and DPf sensors are not easily swapped,... but DPF inlet/outlet sensors/plugs can be improperly swapped, as the cables are actually long enough for this to happen.

May be that your egr valve is getting stuck? causing too high DOC inlet temps? or some other egr issue?

Could also be fuel burning against DOC instead of DPF because of exhaust leaks or some other problem...maybe fuel not spraying properly?.

just some things to think about any ways.

BTW: How were those elements cleaned? -- Hopefully not with some kind of liquids or some other half-arssed method... Cleaning those DOC and DPF elements improperly is the death of them/ruins them fairly quickly. Could be that they have simply gone bad.

Thanks for the reply, truck has 550k miles, these filters have not been cleaned in last 300k miles. Can't tell if the previous owner had cleaned them. I am taking it to stealeras$it, will do EGR tune up as well, will update after couple days.