Parts for your 2015 Subaru Forester-Exhaust gasket

2015 Subaru Forester exhaust gasket: what it does and how to look after it

Yes, the 2015 Subaru Forester uses exhaust gaskets. The Subaru Factory Service Manual (FSM) for the SJ-series Forester specifies multiple exhaust gaskets and crush rings at the manifold-to-cylinder head, front pipe/donut joint, intermediate and rear flange joints, and—on 2.0XT turbo models—the turbo-to-downpipe interface. The Subaru electronic parts catalogue (FAST) lists these gaskets as service parts and the FSM instructs technicians to renew them whenever disturbed. Those technical sources make it clear the exhaust gasket is absolutely relevant to this model.

On a 2015 Forester, exhaust gaskets seal the hot gas path so the engine breathes properly and emissions systems work as intended. They’re typically multi‑layer steel (MLS) at the manifold-to-head, a metal/graphite “donut” ring at the front pipe, and flat ring gaskets at the flanges further rear. Turbo variants add a high‑temperature metal gasket at the turbo outlet. When they lose tension from heat cycling, or the hardware corrodes, small leaks start—often before any obvious hole appears in the pipework.

Signs a Forester’s exhaust gasket is on the way out include:

• A ticking sound on cold start that softens as it warms
• Exhaust odour in the engine bay or under the floor
• Sooty marks around a flange or at the manifold-to-head
• Slight loss of pep, rough idle, or a fuel trim fault if the leak is upstream of the O2 sensor

Service advice for owners and workshops:

• Replace any exhaust gasket that’s been disturbed. The FSM calls for renewal rather than re‑use, as crush-style gaskets don’t reliably reseal.
• Use quality OEM‑equivalent gaskets