Parts for your 2013 Subaru Forester-Fuel cap

2013 Subaru Forester fuel cap: purpose, care, and when to replace

Yes, the 2013 Subaru Forester uses a conventional, screw-on, tethered fuel filler cap, so a fuel-cap is absolutely relevant for this model. This is confirmed by the 2013 Forester Owner’s Manual (fuel filler cap instructions: tighten until it clicks) and the Subaru Service Manual for the SH series, which lists the cap as a key part of the Evaporative Emission Control (EVAP) system. These documents note that an improperly secured or faulty cap can trigger an emissions warning light.

On a 2013 Forester, the fuel cap does more than just plug the hole. It seals the tank to keep petrol vapour contained, supports correct EVAP operation, reduces emissions, and helps prevent dust, water, and road grime from entering the filler neck. When the cap’s ratchet clicks as it’s tightened, it’s confirming the seal is engaged and the system can hold the slight vacuum and pressure changes the EVAP system expects.

As part of routine servicing, it’s smart to give the cap a quick once-over. Check the rubber seal for cracking, flattening, or swelling, make sure the tether isn’t broken, and confirm the ratchet clicks firmly. A perished seal or a cap that won’t click can lead to a fuel smell, a “Check Engine” light, and EVAP fault codes such as P0456, P0455, or P0457. If that light comes on after refuelling, re-seat and tighten the cap until it clicks several times and drive a few trips to allow the system to re-test.

When replacing, choose a genuine Subaru or quality equivalent designed for the 2013 Forester (SH series). A cap with the wrong valve characteristics can upset EVAP diagnostics or tank venting. Keep the gasket clean with a damp cloth only—avoid petroleum-based lubricants that can degrade rubber. In dusty or coastal conditions common in Australia and New Zealand, inspect the seal more frequently and wipe the filler neck lip to prevent grit from compromising the seal.

• Tighten until it clicks several times after every refuel.
• Inspect the seal at each service or every 10,000–15,000 km.
• Replace at the first sign of cracks, hardening, persistent fuel smell, or recurring EVAP codes.

Following the factory guidance in the Owner’s and Service Manuals helps keep emissions in check and avoids nuisance warning lights while protecting the fuel system from contamination.

Popular questions

Does a loose fuel cap cause a Check Engine light on a 2013 Forester?
Yes. The EVAP system detects leaks. A loose or damaged cap can set faults like P0457 (cap loose/off). First step is to refit and tighten until it clicks, then drive a few trips. If the light persists, have the system smoke-tested and consider replacing the cap.

How often should the fuel cap be replaced?
There’s no fixed interval, but many owners replace the cap around the 5–10 year mark or at the first signs of seal damage, weak ratchet action, fuel odour, or recurring EVAP codes. Inspect the seal at each service and replace proactively if it’s hardened or cracked.

Can any universal cap fit the 2013 Forester?
Not reliably. The Forester’s EVAP system expects specific venting and sealing characteristics. Use a genuine Subaru cap or a high-quality direct equivalent specified for the 2013 Forester (SH). The wrong cap can cause drivability issues and warning lights.