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for dealers ordering vehicles in YF5 or NE1 emission states.
Also described as Emissions override, state-specific, between YF5 and NE1 states
Also documented for BuickCadillacChevrolet
Documented applications
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; for dealers ordering in YF5 or NE1 emissions states
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; O on all trims; for dealers ordering vehicles in YF5 or NE1 emission states
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; O on all trims
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; O on all trims
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SUV guide wording: Emissions override, state-specific (lets a California dealer order NE1 emissions). the state list in GM's text changed between the 2025 and 2026 guides. 2025: O in 1SF, 1SG; 2026: O in 3VL, 1SF, 1SG.
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; O: Cargo 1WT, Cutaway 1WT, Cutaway 2WT (2025–2026), Passenger 1LS, Passenger 1LT
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; for dealers ordering vehicles in YF5 or NE1 emission states
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; lets dealers swap between YF5 and NE1 emissions; 2018: GM's 2018 Sierra 2500HD order guide; 2019: GM's 2019 Sierra 3500HD order guide
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for dealers ordering vehicles in YF5 or NE1 emission states
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; O on all trims; for dealers ordering YF5 or NE1 emissions vehicles; requires YF5 or NE1 (2027)
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; 2018 from GM's 2018 Yukon order guide
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2027: O on all trims
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2027: O on all trims
This page aggregates every documented appearance of NB9 in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.