Cali Emissions? It gets worse...

[Turbo OM617]

I think you need to do a little more research...

My bus fleet has both active (MY2008) and passive (MY2006) systems.
The passive systems plug with high idle time (winter) but take 45 minutes to remove the DPF, power wash the filter and get back on the road. Haven't had one crack from normal use (only a few failed when a turbo or engine fails).
The active systems frequently clog the catalyst every 500 hours of operation and burn out the DPF every summer due to the programmed mandatory active regen every 24 ECM hours (no matter the DPF soot load).

45 minutes of shop labor every few months to clean the DPF.
Vs.
45 minutes of shop labor every few months to clean the cat and $3500 to replace a melted DPF once per year.

So its actually YOU that needs to do some research. The passive systems are far less stressful on the engine and a fleet/owner's budget.
The reason they are not used anymore is difficult integration with engine management to minimize emissions.

For passive systems its relatively trivial to hollow out the cat/DPF segments and put a muffler inside so there isn't excessive noise to give up the ruse.

 

[Ruger_556]

So its actually YOU that needs to do some research.

This is what I was referring to actually...

At that point, its as simple as removing the filter and washing out the ash using a pressure washer.

You must be registered for see images attach

 

[Turbo OM617]

This is what I was referring to actually...

Is completely false.
Its perfectly fine to wash out a DPF and DOC with a pressure washer. The "warning" you saw was actually just "legalese" to prevent monkeys that don't know what they're doing from damaging the DPF/DOC. You know, the kind of people that would put a pressure washer nozzle 2" from a radiator or attempt to use soapy water thinking it will clean the DPF/DOC better (some soaps have high sulfur which will foul the DOC).
I have washed out many of our buses DPF/DOC with a pressure washer. None have cracked, plugged up sooner than average or failed in any way.
They keys are you have to blow out the remaining water with high pressure air before installation, drip draining will not work. After installation you must let the engine run for 30 minutes on fast idle (1000rpm) to boil out the remaining moisture before the vehicle is allowed to be driven.
Blowing out the filter with high pressure air makes the cleaning much easier. But, you must use a high flow 1/2" air valve (I use a traditional ball valve for maximum flow) and 1/2" hose with at least a 100 gallon air tank, a normal shop 1/4" air nozzle will NOT work.

 

[towcat]

this is the reason why BAQMD doesn't like the user serviceable DPF systems. too many opinions on how to clean them.