GM Firebird 1967-1981 Repair Guide

Evaporative Emissions Control System


This system, standard since 1970, eliminates the release of unburned fuel vapors into the atmosphere. The only periodic maintenance required is an occasional check of the connecting lines of the system for kinks or other damage and deterioration. Lines should only be replaced with quality fuel line or special hose marked EVAP. On 1970 and 1971 vehicles, the filter in the bottom of the carbon canister, which is located in the engine compartment, should be removed and replaced every 12,000 miles or 12 months. On 1972-76 vehicles, this service interval is 24,000 miles or 24 months. For 1977-81 vehicles, the mileage interval was increased to 30,000 miles, while the time interval remains the same. For further details on the Evaporative Emission Control System please refer to Driveability And Emissions Controls .


  1. Tag and disconnect all hoses connected to the charcoal canister.
  3. Loosen the retaining clamps and lift out the canister.
  5. Grasp the filter in the bottom of the canister with your fingers and pull it out. Replace it with a new one.
  7. Installation of the remaining components is in the reverse order of removal.