Parts for your 2017 Subaru Forester-Fuel cap

2017 Subaru Forester Fuel Cap

Yes, the 2017 Subaru Forester uses a conventional, screw-on fuel filler cap. This is confirmed by Subaru’s technical literature: the 2017 Forester Owner’s Manual details opening the fuel filler lid and tightening the fuel filler cap until it clicks, and the Subaru Service Manual references EVAP system checks where an improperly sealed or faulty cap can set a small-leak diagnostic (often seen as a check engine light). Unlike some capless systems used by other brands, the Forester of this model year is fitted with a tethered, seal-type cap across both petrol and diesel variants sold in Australia and New Zealand.

The fuel cap on a 2017 Subaru Forester does more than just keep dust and rain out. It seals the tank to maintain correct pressure in the evaporative emissions (EVAP) system, helping reduce hydrocarbon vapours from escaping to the atmosphere. A healthy cap—with an intact O-ring and functioning pressure/vacuum valves—supports smooth refuelling, consistent engine performance, and compliance with emissions rules. If the cap isn’t tightened until it clicks, or if the seal is perished, the car may log an EVAP leak code and illuminate the check engine light after a fill-up.

As part of routine servicing, it’s smart to give the cap a quick once-over. Check the rubber seal for cracks, flattening or hardening, make sure the tether isn’t frayed, and ensure the cap clicks firmly when tightened. A light wipe of the sealing face on the neck and the cap’s gasket keeps grit from compromising the seal. If there’s a petrol smell near the rear quarter, a recurrent EVAP code (such as P0456), or the cap no longer clicks positively, replacement is inexpensive and worthwhile. Using a genuine, EVAP-rated cap designed for the SJ-series Forester is recommended to maintain the correct seal and valve characteristics.

There’s no hard replacement interval, but many owners opt to replace the cap proactively around the 5–7 year mark, or sooner if the vehicle lives in hot, sunny or coastal conditions that can age rubber more quickly. Whether the Forester runs on petrol or diesel, the principle is the same: the right cap, fitted snugly, helps the EVAP system do its job and keeps the dash light off.

• Tighten until it clicks after every refuel.
• Inspect the gasket and tether at each service.
• Replace the cap if seals are cracked, the cap won’t click, or EVAP faults persist.

Popular questions

What type of fuel cap does a 2017 Subaru Forester use?
It’s a tethered, screw-on EVAP-rated cap designed to seal the tank and work with the vehicle’s emissions system. Genuine caps are engineered for the Forester’s specific filler neck and pressure/vacuum requirements.

Using the correct cap matters—universal or vented caps can cause sealing issues, fuel smells, or a check engine light.

Why did the check engine light come on after refuelling?
A loose or failing fuel cap is a common cause. If it wasn’t tightened until it clicked, the EVAP system may detect a small leak and trigger a fault code.

Re-tighten the cap and drive a few trips, the light may clear. If it persists, the cap seal may be perished or there could be another EVAP leak that needs diagnosing.

How often should the fuel cap be replaced?
There’s no fixed kilometre limit. Many owners replace the cap every 5–7 years, or earlier if the gasket is cracked, the cap won’t click, or EVAP codes recur.

Harsh climates, lots of sun, or frequent refuelling can age the seal faster, making earlier replacement good preventative maintenance.