"EGR DELETE" Instructions

The EGR delete is intriguing because in many countries like Brazil, they do not have EGR in Prius 3. EGR is one of the biggest enemy in Diesel engine after DPF fuel dilution problems because the shoot from Diesel is much more and become abbrasive to the engine. Many folks delete it completely in states that do not require it.

 

Toyota may make other changes in the Prius they make without EGR, say run the engine a little richer.

 

I doubt that, it will increase fuel consumption. The old fashioned way, just opened the exhaust valve during the intake cycle works fine in Older Corolla and Camry did it that way, it is just not cooled and maybe not as efficient in reducing NOx.
NOx is pollutant for human but food for plants. It becomes Nitrate when reacts with water. Newer cars also start having GPF, shoot filter. Not sure if the 5th gen has one.
EGR is one of the source of engine wear because soot got sucked in and it is abrasive. Routing it after the catalytic converter is a smart move. Reduce the sludgy oil, carbon soot, and radicals.