Gates 31843Y Fuel Tank Cap

Flex Fuel Fuel Cap for GM Applications

The Gates Flex Fuel Regular Fuel Cap, part number 31843Y, is a yellow fuel tank cap marked for E85 use to help identify flex-fuel vehicles at a glance. It is built with a Quick-On cam type and vacuum-only venting for the listed GM applications.

• Yellow plastic cover with E85 designation for flex-fuel identification
• Quick-On cam type for the specified filler neck applications
• Vacuum-only venting
• Thread diameter: 1.56 in.
• Shell diameter: 2.75 in.
• Depth: 2.05 in.
• Not lockable

Product Details

Gates 31843Y is a Flex Fuel Regular Fuel Cap for vehicles that use gasoline or E-85 ethanol. The yellow cap color and E85 marking provide a clear visual cue for drivers and service technicians, while the vacuum-only design matches the listed fuel system requirements. This fuel tank cap is cross-referenced to Stant 10841Y for the same application. Common search terms for this part include flex fuel fuel cap for Chevrolet Impala, GMC Sierra fuel tank cap, and yellow E85 gas cap for GM trucks and SUVs.

Compatible With select 2004-2014 Chevrolet, GMC, Buick, and Cadillac models, including Chevrolet Impala, Malibu, Silverado, Tahoe, Suburban, Avalanche, Express vans, and GMC Sierra, Yukon, and Savana applications. The Gates 31843Y part number is also used in searches for GM flex fuel fuel cap replacement and E85 fuel cap for Chevrolet Silverado 1500.

What This Fuel Cap Helps Address

• Missing or damaged fuel tank cap on listed flex-fuel vehicles
• Incorrect cap identification on E85-capable GM applications
• Fuel system sealing concerns related to a worn cap
• Service replacement needs for Quick-On style filler necks
• Replacement searches for yellow flex fuel caps on Chevrolet and GMC models

Installation Notes and Tips

Verify the filler neck style, thread diameter, and venting specification before installation. This cap uses a Quick-On cam type and is not lockable. Confirm vehicle fitment by year, make, and model, especially on Chevrolet Impala, Silverado, Malibu, Tahoe, and GMC Sierra applications. The 31843Y fuel cap is intended for the listed flex-fuel vehicles only.

Quality Assurance

Gates manufactures fuel system hardware for OE-style replacement applications, and this cap follows the listed dimensional and venting specifications for the confirmed fitments. Use the vehicle fitment data to match the correct GM flex fuel application before purchase.