The EPA regulates engines, not the final equipment "tractors for example. So be sure to look at the engine model year to understand the emissions requirements. Tier4i was primarily a NOx reduction requirement, tier 4 final was a NOx and PM requirement. Diesel engines, when tuned to reduce NOx...
I'm having trouble finding the right filters - the owners manual is useless, the filters have no writing on them, and the dealer is a 2 hour drive - one way. I have a MT342 HST - any help is appreciated. I do have a NAPA about 30 minutes away, so that's my target :)...