Emission system, GVW less than 8,500 lb

Years 1998–10 Models 11 Factory citations 51

Also described as Emission system, GVW less than 8500 lbsEmission system, GVW under 8,500 lbEmission system, GVW less than 8,500 lbsEmissions, GVW 8,500 lb or less

Also documented for Cadillac GMC

Documented applications

Avalanche — GMT800 (2002–2006)

2002, 2004–2006 Factory-verified internal

GM factory document — 2002 chevrolet avalanche 2wd rpo code list, p.1.
GM factory document — 2004 chevrolet avalanche 2wd rpo code list, p.1.
GM factory document — 2005 chevrolet avalanche 2wd rpo code list, p.1.
GM factory document — 2006 chevrolet avalanche 2wd rpo code list, p.1.

C/K pickup — GMT400 (1988–2000)

1998–2000 Factory-verified internal

GM factory document — 1998 chevrolet chevy c pickup 2wd rpo code list, p.1.
GM factory document — 1999 chevrolet chevy c pickup 2wd rpo code list, p.1.
GM factory document — 2000 chevrolet chevy c pickup 2wd rpo code list, p.1.

Express — GMT600 (1996–2002)

1998–2002 Factory-verified internal

the 1998–2000 lists read "Under 8,500 Lbs GVW"; the 2001–2002 lists print "GVW Above 8500 LB", the same as NA4

GM factory document — 1998 chevrolet express rpo code list, p.1.
GM factory document — 1999 chevrolet express rpo code list, p.1.
GM factory document — 2000 chevrolet express rpo code list, p.1.
GM factory document — 2001 chevrolet express rpo code list, p.1.
GM factory document — 2002 chevrolet express rpo code list, p.1.

Express — GMT610 (2003–2027)

2003–2010 Factory-verified internal

; the 2003–2006 lists print Above 8500 for NA1, the same wording as NA4

GM factory document — 2003 chevrolet express rpo code list, p.1.
GM factory document — 2004 chevrolet express awd rpo code list, p.1.
GM factory document — 2005 chevrolet express awd rpo code list, p.1.
GM factory document — 2006 chevrolet express rpo code list, p.1.
GM factory document — 2007 chevrolet express awd rpo code list, p.1.
GM factory document — 2008 chevrolet express rpo code list, p.1.
GM factory document — 2009 chevrolet express rpo code list, p.1.
GM factory document — 2010 chevrolet gh van elec 1 7 d1 100813, p.15.

Silverado — GMT800 (1999–2007)

1999–2000, 2002–2007 Factory-verified internal

2005–2007: heavy-duty models only (GM’s HD list)

GM factory document — 1999 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2002 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2007 chevrolet silverado classic 2wd rpo code list, p.1.
GM Heritage factory kit — 2000 Chevrolet Truck and Silverado, p.57.
GM Heritage factory kit — 2007 Chevrolet Silverado, p.60.

Silverado HD — GMT800 (2001–2007)

2002–2007 Factory-verified internal

GM factory document — 2002 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2003 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2004 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2005 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2006 chevrolet chevy c silverado 2wd rpo code list, p.1.
GM factory document — 2007 chevrolet silverado classic 2wd rpo code list, p.1.

Silverado HD — GMT900 (2007–2014)

2007–2008 Factory-verified internal

GM factory document — 2007 chevrolet silverado 2wd rpo code list, p.1.
GM factory document — 2008 chevrolet silverado 2wd rpo code list, p.1.

Suburban — GMT400 (1992–1999)

1998–1999 Factory-verified internal

GM factory document — 1998 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 1999 chevrolet chevy suburban 2wd rpo code list, p.1.

Suburban — GMT800 (2000–2006)

2000, 2002, 2004–2006 Factory-verified internal

GM factory document — 2000 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 2002 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 2004 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 2005 chevrolet chevy suburban 2wd rpo code list, p.1.
GM factory document — 2006 chevrolet chevy suburban 2wd rpo code list, p.1.
GM Heritage factory kit — 2000 Chevrolet Suburban, p.47.
GM Heritage factory kit — 2002 Chevrolet Suburban, p.37.

Tahoe — GMT400 (1995–1999)

1998–1999 Factory-verified internal

GM factory document — 1998 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 1999 chevrolet tahoe 2wd rpo code list, p.1.

Tahoe — GMT800 (2000–2006)

2000, 2002, 2004–2006 Factory-verified internal

GM factory document — 2000 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2002 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2004 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2005 chevrolet tahoe 2wd rpo code list, p.1.
GM factory document — 2006 chevrolet tahoe 2wd rpo code list, p.1.
GM Heritage factory kit — 2000 Chevrolet Tahoe, p.47.
GM Heritage factory kit — 2002 Chevrolet Tahoe, p.30.

This page aggregates every documented appearance of NA1 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.