Parts for your 2009 Lexus Is-Manifold gasket

2009 Lexus IS manifold-gasket: what it does and when to replace it

Per the Lexus IS 2006–2013 Repair Manual (Toyota Technical Information System) and the Toyota/Lexus Electronic Parts Catalogue for the GSE20/21/22 series, the 2009 Lexus IS does use manifold-gaskets. Both the intake manifold-to-cylinder head and the exhaust manifold-to-cylinder head joints rely on dedicated manifold-gaskets, and the factory guidance specifies replacing them whenever the manifold is removed, with correct torque sequences on refit.

On the 2009 Lexus IS—whether it’s running the 4GR‑FSE (IS 250) or 2GR‑FSE (IS 350) V6—the manifold-gasket has a simple but crucial job: keep the seal tight where the manifold meets the cylinder head. On the intake side, a healthy manifold-gasket prevents unmetered air sneaking in, which would otherwise cause lean running, rough idle, and higher fuel use. On the exhaust side, it locks hot gases inside the runners until they reach the catalytic converters, avoiding power loss, ticking noises on cold start, and that whiffy exhaust smell under the bonnet.

The factory gaskets are designed to cope with heat cycling, vibration, and slight movement as the alloy manifold and steel hardware expand and contract. Over time, composite or multi‑layer steel gaskets can harden or compress, especially if the manifold’s been off before. That’s why Lexus’ service literature flags them as “non‑reusable” items—fit new ones whenever the intake or exhaust manifold is removed for jobs like injector work, carbon cleaning, or exhaust repairs.

Good servicing practice on a 2009 Lexus IS manifold-gasket looks like this:

• Always clean mating faces carefully—no gouging the aluminium