Aftertreatment system

I would say take it in and have the engine put on the analyzer, check turbo pressure, cylinder compression and all of the other factors that causes an engine to produce excess soot.

 

I had an injector that was going bad that caused something like this once. There weren't really any noticeable symptoms or codes, other than the soot level going to max and derating. Parked regens cleared the soot level, but I could also drive derated and it would fall to the A and then derate and climb again. Eventually it failed and started running bad, finally throwing a code for injector #2.

You might be able to find a tool like OTR Performance to reset the soot level every time you stop without running a regen. It's not a good permanent solution, though. I wish I knew a better way to diagnose it for you, because throwing parts at it is never fun. A 6 pack of injectors is not cheap.

 

@nasriza Is the guy to ask on this one.

 

I know you don't have a cummins but I'm sure the idea here is the same, the injector that feeds the exhaust system has to be addressed, watch the first half or so of this video (features cummins)

 

they have to check operation on your egr and try to do a snap test to see how much soot your engine is putting out souds like engine is putting out soot and loading up the filters quickly, this is where i would start also check overhead mainly if any engine brake is getting stuck have you experience any loss of power would be my first question also might be worth the gamble to change the two pipes on dpf for the delta p sensor sometimes they like to get plugged as well and ask for a lot of regen. Hope this helps if anything else you need let me know.

 

Did they clean the DOC? That should be cleaned when the DPF is cleaned. DOC stands for Diesel Oxidation Catalyst. The DOC is similar to the SCR (Selective Catalyst Reduction) and a catalytic converter on a car. They have precious metals that wear off and become inert over time and don't/can't do what they were designed to do. Given your mileage you likely need a DOC. But as was stated in other posts things upstream need to be working properly as in injectors, correct valve adjustment, no leaks...... Has anyone checked the air filter?

 

I'm far from an expert, but the DPF was baked..... how old was the DPF, and was it baked before? If the DPF is old,and has been baked once, baking it again generally doesn't do much good.