Model conversion, up level version

Years 2005–07 Models 1 Factory citations 3

Also documented for Chevrolet Pontiac Saturn

Documented applications

Terraza — U-body / GMT201 (2005–2007)

2005–2007 Factory-verified

GM prints Y9I with a letter I and Y91 with a digit one, a different part, so both stay

GM factory document — 2005 buick terraza rpo code list, p.1.
GM factory document — 2006 buick terraza rpo code list, p.1.
GM factory document — 2007 buick terraza rpo code list, p.1.

This page aggregates every documented appearance of Y9I in the Buick reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.