By law, each vehicle is equipped with a Vehicle Emission Control Information (VECI) label which is permanently affixed. On the models covered in this guide, the label will be found in the engine compartment with typical locations being on the underside of the hood, the top of the radiator, the alternator bracket and the air cleaner box.
The VECI label provides a vacuum schematic for the vehicle in question. Because vacuum circuits will vary based on year, various engine and vehicle options, always refer first to the vehicle emission control information label.
VECI labels are designed to be permanently attached to the vehicle and cannot be removed without being destroyed. Absence of the label in your vehicle may indicate undocumented repair work has been performed.
If you wish to obtain a replacement emissions label, most manufacturers make the labels available for purchase.