Prevent EGR troubles?

Doing some searching as to why they used an equation for PM. When they moved from Tier 2 (pre-2017) to Tier 3 (2017+) gasoline the particulate matter (PM) or soot generated by the gasoline was so small that it was much greater than the PM of the surrounding air. So they characterized the PM generation vs sulfur (presumably from an earlier report). They are collecting from a fleet of over 100 cars and experimenting at different sulfur levels so I think this is warranted (page 76):

Totally agree. The report actually has a total of 178 pages. And this is the Final Report. I bet there are far more graphs and hundreds more pages in the previous reports.

 

The dealer probably won't do a cleaning... they will replace the part according to the service bulletin. It might be necessary to replace the intake manifold also if it got oiled up. The two things go together to produce rough running if they get clogged... or even a blown head gasket. Replacing the parts once and for all is cheap insurance and it's what the dealer probably has to do.

 

Worth every penny, relative to hg or engine replacement

 

To replace perfectly serviceable components instead of cleaning is absurd. Don’t even approach the dealership on this; they’re hopeless. Apart from a few common sense places (Tampa Hybrids and Hybrid Pit Stop for two), DIY is the best option, to get it done right.

 

... but make sure to take the valve apart and eyeball the ski-jump-shaped stop inside the rotor, make sure it isn't mashed. Mashed would be a reason to replace the valve.