Subaru Forester: Common Codes & Fixes

Real-world diagnostic data for the Subaru Forester. These are the codes techs see most often. Tap any code for the full vehicle-specific fix and the exact part.

13 codes have specific fixes for the Subaru Forester
P0129 BARO low on Subaru EJ25 — combined MAP/BARO sensor fails intermittently. 2006-2012 · Easy DIY · 30-45 min P0302 Cylinder 2 on the boxer engine is the passenger-side rear cylinder. 2010-2019 · easy DIY · 30 min P0304 Cylinder 4 on the boxer engine is the driver-side rear cylinder. 2010-2019 · easy DIY · 30 min P0411 Check the secondary air pump relay and fuse first. 2008-2016 · Easy DIY · 0.5-1 hour P0418 P0418 on Subaru is almost always a failed secondary air injection pump relay that sticks on or shorts. 2006-2014 · easy DIY · 15 min P0420 Subaru boxer engines run catalytic converters very close to the engine. 2009-2020 · easy (gasket) DIY · 30 min (gasket), 2 hours (cat) P0421 Subaru boxer engines use individual warm-up cats on each header pipe. 2010-2020 · moderate to hard DIY · 2-3 hours P0447 Subaru mounts the EVAP vent valve near the charcoal canister under the rear of the vehicle. 2010-2020 · moderate DIY · 30-45 min P0456 Subaru EVAP systems are very sensitive to small leaks. 2009-2020 · easy (cap) DIY · 5 min (cap), 1 hour (further diagnosis) P0457 Subaru P0457 is almost always the gas cap. 2010-2020 · easy (cap), moderate (grommet) DIY · 5 min (cap), 1 hour (grommet) P0491 Subaru Secondary Air Injection pump fails after water intrusion -- the pump lives in the fender well and rusts internally. 2006-2014 · moderate DIY · 2 hours P2101 Subaru Forester/Impreza P2101: internal throttle body motor failure. 2011-2018 · easy DIY · 30-45 min P3080 On Subaru, P3080 indicates the engine isn't reaching operating temperature within the expected time window. 2008-2014 · Moderate DIY · 1-2 hours

Frequently Asked Questions

What are the most common check engine light codes on a Subaru Forester?

The most commonly reported OBD-II codes for the Subaru Forester include P0129, P0302, P0304, P0411, P0418. Each code indicates a specific issue -- tap any code above for the full diagnostic breakdown.

How much does it cost to fix a check engine light on a Subaru Forester?

Repair costs vary by code. Many Subaru Forester fixes like gas cap replacement, sensor cleaning, or spark plug changes are under $50 in parts and can be done at home. More complex repairs like catalytic converter or transmission work can run $500-$2,000+ at a shop.

Can I drive my Subaru Forester with the check engine light on?

It depends on the code. A steady check engine light usually means you can drive short distances safely. A flashing check engine light means stop driving immediately -- continued driving can cause serious engine damage. Scan the code first to know what you are dealing with.

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