Difference between engine harness and emission harness?

What's the difference between the engine harness and emission harness? The schematics specify that they are different harnesses, but my engine harness has connectors on it that the schematics say are on the emission harness. If I look at the pinouts for the ECU on the wiring supplement, it clearly states that they attach to (EM) which is the emission harness instead of (E) which is the engine harness. Yet those connectors are on the engine harness.

All the other labels in the diagram seem to make sense. Some connectors are labeled with (D) which is the dash harness, others have (F) which is the front harness, and some have (R) which is the rear harness. Yet my engine harness has (E) on the illustration but (EM) in the diagram itself.