Parts for your 2017 Subaru Impreza-Fuel cap

2017 Subaru Impreza fuel cap — what it does and how to look after it

For the 2017 Subaru Impreza, a conventional screw-on fuel filler cap is absolutely used and relevant. Technical sources back this up: the 2017 Subaru Impreza Owner’s Manual (refuelling section) instructs drivers to tighten the cap until it clicks, the Subaru Service Manual for the GK/GT series details the fuel lid and cap assembly, and Subaru’s genuine parts catalogue lists a dedicated fuel filler cap for this model range. On top of that, ADR 79/04 and OBD‑II evaporative emissions requirements mean the system relies on a sealed cap to pass self-checks.

On this Impreza, the fuel cap does more than just close the tank. It seals petrol vapour, supports the EVAP system so the car doesn’t throw a check engine light, and keeps dust and water out — handy across Aussie and Kiwi roads where conditions can be a bit harsh. The tether stops it going walkabout at the servo, and the clicker mechanism makes sure it’s tightened correctly without overdoing it.

As part of regular servicing, it’s smart to give the cap a quick once-over. If there’s a faint smell of petrol around the rear guard, or the dash lights up with small‑leak EVAP codes after refuelling, the cap and its rubber seal are usual suspects. Age, heat and UV can harden the gasket, and grit on the filler neck can stop it sealing.

• Wipe the cap’s sealing face and the filler neck lip with a clean, lint‑free cloth.
• Don’t lube the gasket with oils or silicone — just keep it clean and pliable.
• Always tighten until it clicks several times after refuelling.
• If the tether is broken, the gasket is cracked, or EVAP warnings persist, replace the cap.

When replacing, use a genuine Subaru cap (or a quality equivalent built for the 2017 GK/GT Impreza). The wrong cap can cause ongoing EVAP faults, rough starts after fill‑ups, or fuel odours. Fitment is as easy as unscrewing the old cap, checking no old O‑ring is stuck to the neck, then installing the new one and clicking it tight. If a check engine light came on due to a loose cap, it will usually clear itself after a few normal drive cycles once the system passes its leak test.

Popular questions about 2017 Subaru Impreza fuel caps

Does the 2017 Impreza have a capless fuel filler?
No — it uses a screw-type, tethered fuel cap. Subaru’s 2017 Impreza Owner’s Manual calls out tightening the cap until it clicks, and the parts catalogue lists a dedicated filler cap for this model.

Why did the check engine light appear after refuelling?
Most of the time it’s a loose or worn fuel cap triggering an EVAP small‑leak fault. Refit the cap and click it tight, then drive normally, the light often clears after the system runs its self‑checks. If it keeps coming back, inspect the cap’s seal or replace the cap before chasing other EVAP leaks.

Which replacement cap should be used?
Choose a genuine Subaru cap or a high‑quality equivalent specified for the 2017 GK/GT Impreza petrol models. That ensures the correct pressure/venting behaviour and a proper seal, helping avoid repeat EVAP warnings.