Mazda Fuel Tank Cap OEM 31720

This Gates fuel tank cap for Mazda restores the EVAP-system seal and clears the check-engine light.

The gasketed, vented fuel tank cap holds the EVAP system's positive pressure and vacuum bleed. A leaking cap is one of the top causes of an EVAP check-engine light.

Verify your fitment with the year, make, model, and trim of your vehicle before ordering. If you are not sure, contact us with your VIN or vehicle configuration and we will match the correct part to your application before you buy.

Cross-Reference

Manufacturer part number 31720. This is a Gates catalog part. Confirm the OE reference for your vehicle matches before installing.

Why You Might Need This

A vented cap that no longer holds pressure is one of the top EVAP check-engine-light causes. Confirm with a smoke test before chasing hoses.

Installation Notes

Confirm the cap seats with the three-click stop indicator on modern caps. A partially seated cap will produce EVAP codes even with a new cap.

Shipping and Returns

Free shipping on orders over $75. Same-day shipping on in-stock parts ordered before 2:00 PM CT weekdays. Orders placed after the same-day cutoff ship the next business day. Every order ships from our climate-controlled warehouse; parts do not sit outside where humidity and temperature swings could damage packaging.

30-day return window on unopened, unused parts in original packaging. Open parts installed without verified fitment: no return, or up to a 40 percent restocking fee depending on condition. Brake friction material (pads and shoes) is safety-critical and cannot be returned once a pad has touched a rotor. If a part does not fit your vehicle as described, we cover the return shipping and make it right.