Fuel Tank Cap Fuel Tank Cap by Stant. OE Equivalent Without Locking. A defective fuel cap can cause your vehicle to fail an emissions test and allow up to 22 gallons of gasoline to evaporate in one year wasting your money and polluting the environment. A Stant replacement fuel cap includes all required safety features and valving and meets or exceeds all OE performance and safety standards. Features OE Pressure relief prevents fuel vapors from exiting the fuel system under normal operating condition OE Vacuum relief prevents fuel vapors from exiting the fuel system via the fill tube under normal operationCompatibility: 1997-2005 Buick Century 2003-2004 Cadillac CTS 1997-2005 Chevy AstroSpecifications Cam Type: Quick-On Venting: Emission Control Neck Diameter: 1.56 Shell Diameter: 2.78 Cap Depth: 2.41 - SKU: PRTST40464