Parts for your 2021 Honda Odyssey-Exhaust gasket

2021 Honda Odyssey exhaust gasket: what it does and when to replace it

According to Honda’s Factory Service Information for the 2018–2023 Odyssey and the Honda Genuine Parts catalogue for the 2021 model year, the Odyssey’s 3.5‑litre V6 exhaust system uses multiple exhaust gaskets. These include exhaust manifold-to-cylinder head gaskets and crush-style “donut” gaskets at spring‑bolted flanges in the front pipe/catalyst connections. Aftermarket technical catalogues from major gasket makers also list manifold and front pipe gaskets for this vehicle, confirming their fitment.

On a 2021 Odyssey, exhaust gaskets have a straightforward job: keep hot exhaust gases sealed inside the system so the engine management can read clean data from the oxygen sensors, the cabin stays free of fumes, and the note from the tailpipe remains civilised. At the manifold, multi‑layer steel (MLS) gaskets cope with high heat and expansion. Downstream, graphite or metal crush gaskets seal the flanged joints where the pipes flex and move with the engine.

There isn’t a time‑based replacement schedule for exhaust gaskets. Instead, they’re replaced whenever a joint is disturbed or if a leak shows up. Honda service procedures specify using new gaskets any time the manifold, catalytic converter assembly, or front pipe is removed. Reusing a crush gasket is a false economy—once compressed, it won’t reliably reseal.

What should an Odyssey owner or tech look out for? A light ticking or hissing on cold start that quietens as it warms up, a whiff of exhaust near the engine bay, soot traces around a flange, or fuel trims and O2 sensor readings that wander. Left unattended, a small leak can skew mixture control, trigger fault codes, and roast nearby components.

• Always fit quality OEM‑equivalent gaskets