Temporarily driving with dpf filter removed

Doser got moved to the top of the pipe. It also got the new outward opening style that no longer needs cleaning. Cant recall ever cleaning one

Egr and air managment sensors requiring cleaning for all years

 

Only time I clean the newer style OOP HC doser is when cleaning a DPF. Our EPA-10's are starting to creep very close to 800,000 miles/20,000 hrs, kinda been warned that is SCR catalyst death mileage for them. Hopefully they get traded in soon.

 

EGR was dialed back and more DEF is used. So to say they can be slightly less soot under the same operating conditions would be accurate. But only slightly.

50% idle time and less than 20% load will lead to annual cleaning of everything regardless of engine year.

 

What kills the SCR catalyst?
The frequent regens?

 

Generally speaking I think the Catalyst does degrade slighty over time. I dont replace a ton of SCR on MX product. More often replace for stripped sensor bung than for a conversion problem. Way more on Cummins for some reason, especially midrange engines.

DOC do not hold up well to repeat oil or coolant contaminants. Cells become blocked with caked in residue and efficiency is reduced. Before you know it you cant maintain temps for good regens. I do not agree with baking a DOC for cleaning. Flush with clean water ( not a power washer) and inspect, if data shows poor performance it gets a new one.

 

You think it would be significant consequences if you don’t fix the after treatment soon

 

They advertise in okc right off interstate. The only shops that won’t do it, and most that I’ve heard won’t work on one that has been deleted are the big OEM shops, Rush, KenWorth, etc. al the little shops. Even if they’re a big, little shop. Meaning they’re not a franchise but they have multiple shops around the state. They all do deletes. Except maybe shops in
states like California.

 

They changed the SCR catalyst for EPA13. Went from three bricks to two and precious metals coating was greatly increased. Sintering of the material from heat, trace sulphur from fuel, or coolant/oil/fuel from engine are all killers.
I to have replaced a lot of DOC's on EPA10's. Seems around 600,000 miles on average for our fleet. Usually seems like precious metals washcoat separation. Have mine ultrasonically cleaned.