Certification, emission, geographically restricted registration

Years 1998–00 Models 8 Factory citations 11

Also described as Emission certification, geographically restricted registrationEmissions, geographically restricted (California requirements outside California)Emission system, geographically restricted regions (California requirements outside California)

Also documented for Buick Cadillac Chevrolet Hummer Oldsmobile Pontiac Saturn

Documented applications

Jimmy — second generation (1995–2001)

1999, 2000 Factory-verified internal

GM factory document — 1999 gmc jimmy 4wd rpo code list, p.1.
GM factory document — 2000 gmc jimmy 4wd rpo code list, p.1.

Safari — Second generation (1995–2005)

1998 Factory-verified internal

GM factory document — 1998 gmc safari 2wd rpo code list, p.1.

Sierra — GMT400 (1988–2000)

1998 Factory-verified internal

GM factory document — 1998 gmc gmc c pickup 2wd rpo code list, p.1.

Sierra — GMT800 (1999–2007)

1999–2000 Factory-verified internal

GM factory document — 1999 gmc gmc c sierra 2wd rpo code list, p.1.
GM factory document — 2000 gmc gmc c sierra 2wd rpo code list, p.1.

Sonoma — second generation (1994–2004)

1999–2000 Factory-verified internal

GM factory document — 1999 gmc sonoma pickup 4wd rpo code list, p.1.
GM factory document — 2000 gmc sonoma pickup 4wd rpo code list, p.1.

Suburban — GMT400 (1992–1999)

1998 Factory-verified internal

GM factory document — 1998 gmc gmc suburban 2wd rpo code list, p.1.

Yukon — GMT400 (1992–1999)

1998 Factory-verified internal

GM factory document — 1998 gmc yukon 2wd rpo code list, p.1.

Yukon — GMT800 (2000–2006)

2000 Factory-verified internal

GM factory document — 2000 gmc yukon 2wd rpo code list, p.1.

This page aggregates every documented appearance of NG1 in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.