Parts for your 2013 Subaru Outback-Fuel cap

2013 Subaru Outback fuel cap — what it does and how to look after it

Yes, a fuel cap is absolutely used on the 2013 Subaru Outback. Subaru’s own technical sources confirm it: the 2013 Outback Owner’s Manual specifies a threaded, tethered fuel-filler cap that must be tightened until it clicks, and Subaru service information notes that a loose or damaged cap can trigger EVAP leak fault codes and a Check Engine Light. Subaru’s genuine parts catalogue also lists a replacement “cap assembly – fuel filler” for this model year, underscoring that the vehicle is designed to run with a proper, sealing cap.

On this Outback, the fuel cap does more than just close the filler neck. It seals the tank to keep petrol vapours inside the evaporative emissions (EVAP) system, helps maintain correct tank pressure, and stops dust and water from sneaking into the fuel. That means better air quality, fewer fumes around the car, and a lower chance of hard starts or rough running caused by contamination.

As part of routine servicing, it’s worth giving the cap a quick once-over. The rubber seal should be soft, intact, and free of cracks. If the cap won’t click when tightened, the tether is broken, there’s a whiff of petrol around the left-rear quarter, or the dashboard shows a Check Engine Light after refuelling (often small-leak codes like P0456), the cap is a prime suspect.

When replacing, choosing a genuine or high-quality EVAP-rated cap is smart. It needs to be vented and built to the correct pressure spec so the Outback’s EVAP system tests pass reliably. A cheap, non-vented cap can cause warning lights or refuelling difficulty.

• At each service or every 12 months: inspect the cap seal and wipe away dust from the filler neck.
• After every fill: tighten until it clicks. If it won’t click, replace it.
• If a Check Engine Light appears post-refuel: re-seat the cap, drive a few trips, and have codes scanned if the light stays on.

A well-sealing fuel cap is a small part that protects performance, economy, and emissions—simple to check, cheap to replace, and well worth the peace of mind on long Kiwi or Aussie road trips.

Popular questions about 2013 Subaru Outback fuel caps

What type of fuel cap does the 2013 Outback use?
It uses a threaded, tethered petrol cap that tightens until it clicks. The design is EVAP-compatible to keep vapours contained and ensure the onboard diagnostics can run its leak checks properly.

Why did the Check Engine Light come on after I filled up?
Most commonly, the cap wasn’t fully clicked home, or the seal is worn. Refit the cap until it clicks and drive a few short trips. If the light remains, have the EVAP system checked, the cap is still the first thing to replace.

How often should I replace the fuel cap?
There’s no strict kilometre interval, but replacing it when the seal perishes, the cap won’t click, or there’s persistent fuel odour is wise. Many owners pre-emptively fit a new cap around the 8–10 year mark.