Snowback
Platinum Member
Great continued research AuburnAlum. Lots of good info being shared here. In response to your observation, I believe there should not be a practical need to ever replace a DOC if you choose to go that route. Also - in reality most folks with DPF systems will not be replacing those either unless they use the heck out of them. It might hurt the DPF engine resale value though if getting on up in hours in my opinion.
That engine emission info label notes all of the equipment Shibaura uses in its Tier 4 complaint system. (PCV, EGR, DOC, ECM, etc...). It states that it is EPA and CARB compliant. The next line under the listing of control mechanisms states how long that Shibaura and CARB, (California Air Resource Board), believe that system will effectively control the emissions to within the specifications required for Tier 4. (Its useful life). In the case of this type of engine, it is possible that the catalytic converter itself may not be converting all of the noxious gasses 100% into water and other non offensive compounds and elements after 7 years of use, or 5000 hours. However, barring abuse through dumping solids into the exhaust manifold, (sediment from deep water submersion, running in dirt with no air filter, etc...), the device itself should not be compromised, and exhaust gasses should still be flowing freely through the DOC, (Cat - in old man car terms), and it will simply be less effective at converting the gasses as time passes on. I do not believe there would be any performance drop.
In my opinion the only time you would have to replace a DOC is if you wanted to re-certify it as CARB compliant 15 years from now after using hard every day. Recall that a DOC has no filter or membrane, just a large surface area of plates that are coated with a catalyst. This helps convert the noxious gasses into harmless materials as the gas passes through the DOC. The effectiveness of the catalyst may wane somewhat over the decades, but unless your entire exhaust system rusted out, I honestly feel a DOC will be hard to compromise. Please verify or correct what I am saying if even better info is available. Perhaps your dealer could give you the hotline to Massey's corporate customer service team so you can confirm what you are finding in your search, or hearing from us. I'll admit they will know much more than me, and should be a good source if they are honest with you. I was able to get all of my in depth technical questions answered though a Product Development Manager at Mahindra when I was in your shoes and trying to address similar questions. Can't hurt to ask him... Good luck!
