Parts for your 2016 Subaru Impreza-Fuel cap

2016 Subaru Impreza fuel cap — what it does, why it matters, and when to replace it

For the 2016 Subaru Impreza, a conventional, screw-on fuel cap is very much part of the car. Technical sources that confirm this include the Subaru MY16 Impreza Owner’s Manual (fuel filler lid and cap procedure), the Subaru Service Manual sections on the fuel tank and evaporative emission control (EVAP), and OBD‑II diagnostics that flag loose or leaking caps. Australian Design Rules (ADR 79/04) and equivalent NZ emissions standards also expect a sealed filler system, which the cap provides. So yes—this model absolutely uses a fuel cap, and it’s important.

The fuel cap on a 2016 Impreza does more than just stop petrol sloshing out. It seals the tank so the EVAP system can capture and process fuel vapours instead of letting them escape. That helps the car meet emissions rules, keeps fuel smell to a minimum, and prevents dust and water getting into the tank. A cap that seals properly also avoids nuisance check‑engine lights, because a loose or damaged cap is a common trigger for EVAP leak codes (like P0442 or P0456).

Day to day, the cap is simple: refit it after refuelling and tighten until it clicks. Over‑tightening past the click isn’t helpful, under‑tightening can set a fault light. During routine servicing, it’s worth a quick once‑over: check the rubber seal for hardening or cracks, make sure the tether isn’t broken, and confirm the cap locks on smoothly without cross‑threading.

When should it be replaced? There’s no set interval, but a new cap is smart if there’s a persistent fuel smell around the rear quarter, the cap won’t click tight, the seal looks perished, or an EVAP small‑leak code keeps returning after inspections. Genuine or ADR‑compliant caps designed for Subaru’s EVAP specs are the safest bet, a poor‑quality universal cap can cause sealing issues or compatibility headaches.

• Signs it’s time for a new cap:
  • Fuel odour after parking or refuelling
  • Cap won’t click or feels loose
  • Hardened, flattened, or cracked O‑ring
  • Recurring EVAP leak codes or check‑engine light

• Easy care tips:
  • Wipe dust from the filler neck and cap seal occasionally
  • Avoid forcing the threads, align and turn gently to the click
  • Replace the cap if the tether breaks or the seal looks tired

Looked after properly, the Impreza’s fuel cap is a tiny part that saves time, money, and hassle—quietly keeping the EVAP system happy and the cabin free of fuel pong.

Popular questions about 2016 Subaru Impreza fuel caps

Does the 2016 Subaru Impreza have a capless fuel filler?
No. This model uses a conventional screw‑type fuel cap with a click‑to‑lock action. Subaru’s owner information specifies refitting and tightening the cap after refuelling to maintain EVAP sealing and avoid warning lights.

Why did the check‑engine light come on after refuelling?
A loose or worn fuel cap can trigger EVAP leak codes shortly after a fill. Owners should remove and refit the cap, tighten until it clicks, and drive a few trips so the system can recheck. If the light persists, inspect the cap seal or have the EVAP system smoke‑tested.

Can an aftermarket fuel cap be used?
Yes, provided it’s designed for the 2016 Impreza and meets ADR/NZ compliance for sealed EVAP systems. Genuine or quality OEM‑equivalent caps are recommended to ensure proper venting and sealing. If the cap doesn’t click positively or stops the light from returning, it’s not the right match.