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requires NG1 or YF5.
GM Heritage factory kit — 1994 Chevrolet Astro Van, p.10.
NC7 Factory-verified
Also described as Emission override, federal systemEmission system, override, federalEmissions override, federal (with YF5 or NG1)Emission override, federalEmissions override, FederalEmissions override, federal, for YF5 or NE1 vehiclesEmissions override, federal (with YF5, NG1 or NE1)Emission override, federal, for vehicles ordered in federal emission states with California, New York, Vermont, Massachusetts or Maine emissionsEmission override, federal or high altitudeEmissions override, federal, for YF5 or NE1 vehicles sold in federal statesEmission override, Federal
Also documented for BuickCadillacGMCOldsmobilePontiacSaturn
Documented applications
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The 1995 to 1997 guides print the federal emission override.
GM Heritage factory kit — 1995 Chevrolet Astro Van, p.12.GM Heritage factory kit — 1996 Chevrolet Astro Van, p.17.GM Heritage factory kit — 1997 Chevrolet Astro Van, p.35.
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; 2005 kit: for dealer orders in federal-emission states with California, New York, Vermont, Massachusetts or Maine emissions; requires YF5 or NE1; ; ;
GM Heritage factory kit — 2004 Chevrolet Aveo, p.24.GM Heritage factory kit — 2005 Chevrolet Aveo, p.25.GM Heritage factory kit — 2006 Chevrolet Aveo, p.25.
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cavalier-gen3 also names NE1
GM Heritage factory kit — 1994 Chevrolet Beretta, p.12.GM Heritage factory kit — 1995 Chevrolet Beretta, p.12.GM Heritage factory kit — 1996 Chevrolet Beretta, p.10.
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; 2LT, 3LT, RS: O; Premier: O (2025 only)
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the 1994 guides print a federal or high altitude emission override, requiring NG1 or YF5
GM Heritage factory kit — 1994 Chevrolet Blazer, p.9.
- GM Heritage factory kit — 1994 Chevrolet S 10 Blazer, p.21.
- GM Heritage factory kit — 1995 Chevrolet S 10 Blazer, p.7.GM Heritage factory kit — 1996 Chevrolet S 10 Blazer, p.6.GM Heritage factory kit — 1997 Chevrolet S 10 Blazer, p.13.GM Heritage factory kit — 1999 Chevrolet S 10 Blazer, p.37.
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requires YF5 or NE1
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requires YF5 or NE1
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O: 400, 600;
- GM Heritage factory kit — 1994 Chevrolet Camaro, p.7.GM Heritage factory kit — 1995 Chevrolet Camaro, p.8.GM Heritage factory kit — 1996 Chevrolet Camaro, p.14.GM Heritage factory kit — 1997 Chevrolet Camaro, p.8.GM Heritage factory kit — 1998 Chevrolet Camaro, p.9.
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GM Authority 2014 RPO list
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for vehicles ordered by dealers in federal emission states with YF5 or NE1 emissions;
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requires YF5 or NG1
GM Heritage factory kit — 1994 Chevrolet Caprice, p.13.GM Heritage factory kit — 1995 Chevrolet Caprice, p.7.GM Heritage factory kit — 1996 Chevrolet Caprice, p.11.
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requires YF5 or NE1
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; for dealers in federal states ordering YF5 or NE1 emissions; requires YF5 or NE1
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the Cavalier third-generation doc also names NE1
GM Heritage factory kit — 1994 Chevrolet Cavalier, p.2.
- GM Heritage factory kit — 1995 Chevrolet Cavalier, p.8.GM Heritage factory kit — 2005 Chevrolet Cavalier, p.90.
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; 2018 guide: 1LS, 1LT: O
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; 2015: O on all trims; 2018 from GM's 2018 Colorado order guide (PDF)
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; O on all trims
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same description as beretta-gen1
GM Heritage factory kit — 1994 Chevrolet Corsica, p.10.GM Heritage factory kit — 1995 Chevrolet Corsica, p.8.GM Heritage factory kit — 1996 Chevrolet Corsica, p.6.
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requires YF5 or NG1 (1995)
GM Heritage factory kit — 1994 Chevrolet Corvette, p.25.GM Heritage factory kit — 1995 Chevrolet Corvette, p.23.GM Heritage factory kit — 1996 Chevrolet Corvette, p.83.
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Heritage order guides only: requires YF5, or NG1 on the guides that list it
GM Heritage factory kit — 1997 Chevrolet Corvette, p.7.GM Heritage factory kit — 1998 Chevrolet Corvette, p.8.GM Heritage factory kit — 1998 Chevrolet Corvette, p.10.GM Heritage factory kit — 1999 Chevrolet Corvette, p.16.GM Heritage factory kit — 2003 Chevrolet Corvette, p.110.GM Heritage factory kit — 2003 Chevrolet Corvette, p.117.GM Heritage factory kit — 2003 Chevrolet Corvette, p.126.
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Requires YF5 or NE1.
GM Heritage factory kit — 2005 Chevrolet Corvette, p.99.GM Heritage factory kit — 2006 Chevrolet Corvette, p.111.
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2016, 2019: from GM order-guide copies (Corvette Action Center; 2019 also GM Authority)
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; all: O; for dealers in federal states ordering YF5 or NE1 emissions
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; for dealers in federal-emission states ordering YF5 or NE1 emissions
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for vehicles ordered by dealers in federal emission states with California, New York, Vermont, Massachusetts or Maine emissions.
GM Heritage factory kit — 2005 Chevrolet Equinox, p.90.GM Heritage factory kit — 2007 Chevrolet Equinox, p.92.
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for vehicles ordered by dealers in Federal-emission states with YF5 or NE1 emissions; requires YF5 or NE1
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requires YF5 or NE1
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; O on all trims; for federal-emissions-state dealers ordering vehicles with YF5 or NE1 emissions; requires YF5 or NE1
- GM Heritage factory kit — 1996 Chevrolet G Van, p.51.GM Heritage factory kit — 1997 Chevrolet Express, p.26.
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; the 2006–2009 lists read Emission Override - Federal System; O: Cargo 1WT, Cutaway 1WT, Cutaway 2WT (2025–2026), Passenger 1LS, Passenger 1LT
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1994: requires NG1 or YF5; 1996: requires NG1.
GM Heritage factory kit — 1994 Chevrolet G Van, p.12.GM Heritage factory kit — 1995 Chevrolet G Van, p.5.GM Heritage factory kit — 1996 Chevrolet G Van, p.43.
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; all trims: O; requires YF5 or NE1
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requires YF5 or NG1
GM Heritage factory kit — 1994 Chevrolet Impala, p.4.GM Heritage factory kit — 1995 Chevrolet Impala, p.11.GM Heritage factory kit — 1996 Chevrolet Impala, p.11.
- GM Heritage factory kit — 2000 Chevrolet Impala, p.43.GM Heritage factory kit — 2003 Chevrolet Impala, p.116.GM Heritage factory kit — 2005 Chevrolet Impala, p.101.
- GM Heritage factory kit — 1995 Chevrolet Lumina, p.10.GM Heritage factory kit — 1995 Chevrolet Lumina, p.12.GM Heritage factory kit — 1996 Chevrolet Lumina, p.18.GM Heritage factory kit — 1996 Chevrolet Lumina, p.22.GM Heritage factory kit — 1999 Chevrolet Lumina, p.12.GM Heritage factory kit — 1999 Chevrolet Lumina, p.14.
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1997 from the Malibu kit order guide.
GM Heritage factory kit — 1997 Chevrolet Malibu, p.12.GM Heritage factory kit — 1998 Chevrolet Malibu, p.6.GM Heritage factory kit — 1999 Chevrolet Malibu, p.27.GM Heritage factory kit — 2003 Chevrolet Malibu, p.81.
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; for dealers in federal-emissions states ordering a vehicle with YF5 or NE1
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; all trims: O; for dealers in federal-emissions states ordering YF5 or NE1 emissions; requires YF5 or NE1
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emissions (reqs YF5 or NG1).
GM Heritage factory kit — 1995 Chevrolet Monte Carlo, p.13.GM Heritage factory kit — 1998 Chevrolet Monte Carlo, p.11.GM Heritage factory kit — 1999 Chevrolet Monte Carlo, p.12.
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Also in the kit's Monte Carlo order guide.
GM Heritage factory kit — 2006 Chevrolet Monte Carlo, p.117.
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requires YF5 or NG1
GM Heritage factory kit — 1994 Chevrolet Motorhome, p.5.GM Heritage factory kit — 1995 Chevrolet Motorhome, p.8.GM Heritage factory kit — 1996 Chevrolet Motorhome, p.6.GM Heritage factory kit — 1997 Chevrolet Motorhome, p.4.GM Heritage factory kit — 1998 Chevrolet Motorhome, p.7.
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2001-2002 lists print "Federal Emissions Override System"
- GM Heritage factory kit — 1994 Chevrolet S 10, p.15.GM Heritage factory kit — 1995 Chevrolet S 10, p.10.GM Heritage factory kit — 1996 Chevrolet S 10, p.15.GM Heritage factory kit — 1997 Chevrolet S 10, p.14.
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2025–2027: A in all groups
- GM Heritage factory kit — 2003 Chevrolet Silverado SS, p.207.GM Heritage factory kit — 2007 Chevrolet Silverado, p.56.
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the 2005 list prints it only in its light-duty half; the 2005 2500HD and 3500HD order guides list it
GM Heritage factory kit — 2005 Chevrolet Silverado 2500HD, p.193.
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2017: GM's 2017 Silverado 2500HD order guide; 2018: GM's 2018 Silverado 2500HD order guide; 2019: GM's 2019 Silverado 2500HD order guide
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only in: 2500 HD, 3500 HD, 3500 HD chassis cab
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; all trims: O
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; all trims: O; 2018 from GM's 2018 order guide
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; O; requires YF5 or NE1
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a free-flow option for dealers ordering state-specific emissions, in the kit guides only
GM Heritage factory kit — 2003 And 2004 Chevrolet SSR, p.91.GM Heritage factory kit — 2005 Chevrolet SSR, p.99.
- GM Heritage factory kit — 1994 Chevrolet Suburban, p.8.GM Heritage factory kit — 1995 Chevrolet Suburban, p.12.GM Heritage factory kit — 1996 Chevrolet Suburban, p.7.GM Heritage factory kit — 1997 Chevrolet Suburban, p.14.
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For vehicles ordered by dealers in Federal emission states with YF5 or NE1 emissions; requires YF5 or NE1. Trim marks in the 2014 guide: LS, LT, LTZ: O.
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requires YF5 or NE1; 2018–2019 from GM's 2018 and 2019 Suburban order guides (GM Authority copies)
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2027: O on all trims
- GM Heritage factory kit — 1995 Chevrolet Tahoe, p.4.GM Heritage factory kit — 1996 Chevrolet Tahoe, p.18.GM Heritage factory kit — 1997 Chevrolet Tahoe, p.24.GM Heritage factory kit — 1998 Chevrolet Tahoe, p.42.GM Heritage factory kit — 1999 Chevrolet Tahoe, p.14.
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the guides print it as "Emissions override, Federal" for vehicles ordered by dealers in Federal emission states with California, New York, Vermont, Massachusetts or Maine emissions; the 2003 guide notes it requires YF5, NE1 or NG1
GM Heritage factory kit — 2003 Chevrolet Tahoe, p.123, p.134, p.149.GM Heritage factory kit — 2005 Chevrolet Tahoe, p.123, p.135.GM Heritage factory kit — 2006 Chevrolet Tahoe, p.120, p.131.
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For vehicles ordered by dealers in Federal emission states with YF5 or NE1 emissions; requires YF5 or NE1. Trim marks in the 2014 guides: Police: O; Special Service: O. The 2007 kit also prints it (emissions override).
GM Heritage factory kit — 2007 Chevrolet Tahoe, p.149, p.161.
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requires YF5 or NE1; 2018–2019 from GM's 2018 and 2019 Tahoe order guides (GM Authority copies)
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2027: O on all trims
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; all trims: O; for dealers in federal-emissions states ordering vehicles with YF5 or NE1 emissions
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for vehicles ordered by dealers in Federal-emission states with another state emission system; the service lists do not print it
GM Heritage factory kit — 2003 Chevrolet Trailblazer, p.123.GM Heritage factory kit — 2005 Chevrolet Trailblazer, p.119.GM Heritage factory kit — 2006 Chevrolet Trailblazer, p.134.GM Heritage factory kit — 2007 Chevrolet Trailblazer, p.134.
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for vehicles ordered by dealers in Federal-emission states with YF5 or NE1 emissions; requires YF5 or NE1.
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; all trims: O; for dealers in federal-emissions states ordering YF5 or NE1
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; O on all trims; for dealers in federal-emission states ordering vehicles with YF5 or NE1 emissions
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; all trims: O; requires YF5 or NE1
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all trims: O; for dealers in Federal emission states with YF5 or NE1 emissions
- GM Heritage factory kit — 2005 Chevrolet Uplander, p.100.GM Heritage factory kit — 2006 Chevrolet Uplander, p.113.GM Heritage factory kit — 2007 Chevrolet Uplander, p.111.
- GM Heritage factory kit — 1997 Chevrolet Venture, p.45.GM Heritage factory kit — 1998 Chevrolet Venture, p.23.GM Heritage factory kit — 2003 Chevrolet Venture, p.100.GM Heritage factory kit — 2005 Chevrolet Venture, p.98.
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O; for dealers in federal states ordering YF5 or NE1 emissions; requires YF5 or NE1
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LT, Premier: O; for dealers in federal states ordering YF5 or NE1 emissions; requires YF5 or NE1
This page aggregates every documented appearance of NC7 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.