Parts for your 2002 Subaru Forester-Manifold gasket

2002 Subaru Forester manifold gasket — what it does and when to replace it

Yes, the 2002 Subaru Forester does use manifold gaskets. Both the intake manifold and the exhaust manifold are sealed to the cylinder heads with dedicated gaskets on the EJ25 2.5‑litre flat‑four. This is documented in the Subaru Forester MY2002 Factory Service Manual (Engine/Intake and Engine/Exhaust sections) and the Subaru parts catalogue, and it’s echoed by reputable gasket manufacturers’ listings for EJ25 engines.

The manifold gasket’s job is simple but critical. On the intake side, the gasket keeps unmetered air from sneaking past the manifold into the heads, maintaining correct fuel trims and smooth idle. On the exhaust side, the gasket keeps hot exhaust gases sealed as they leave the heads, preventing ticking noises, fumes under the bonnet, and cooked nearby components. Subaru moved to robust multi‑layer steel styles on many EJ applications because they handle heat cycles and clamping force better than older composite types.

On a 2002 Forester, manifold gaskets aren’t a routine “every X kilometres” service item. They’re replaced when there’s evidence of a leak, or whenever the manifold is removed for other work. If the intake gasket seeps, expect lean codes (often P0171), rough idle, or a tell‑tale hiss. If the exhaust gasket fails, there’s usually a sharp cold‑start tick, soot marks around the flange, and sometimes an exhaust smell in the cabin at idle.

• Listen on cold start for ticking at the exhaust ports