Parts for your 2016 Subaru Impreza-Exhaust gasket

2016 Subaru Impreza Exhaust Gasket — What It Does and When to Replace

Based on the Subaru Factory Service Manual for the 2016 Impreza (GJ/GP, FB20 engine) and Subaru’s Electronic Parts Catalogue (FAST), this model absolutely uses multiple exhaust gaskets. The manual’s Exhaust section identifies manifold-to-head gaskets and ring/flare (“donut”) and flat flange gaskets across the front pipe, centre pipe and muffler joints, making the exhaust-gasket relevant to any exhaust work on a 2016 Subaru Impreza.

On this Impreza, exhaust gaskets seal the joins between hot, high-velocity exhaust stream sections so gases don’t escape before the catalytic converter or muffler. That keeps the car quiet, protects against fumes entering the cabin and ensures the oxygen sensors read correctly, which helps the ECU manage fuel trims and keeps emissions on the right side of a WOF or rego check. You’ll typically find multi-layer steel manifold gaskets at the head, a graphite/steel “donut” gasket at the spring-bolt joint, and flat gaskets at two- or three-bolt flanges further down the system.

As a rule, gaskets aren’t a periodic service item, but they should be inspected any time the car’s on a hoist, and replaced whenever an exhaust joint is disturbed. Subaru’s service literature expects new gaskets on reassembly to ensure a reliable seal. Reusing old ones risks leaks that sound like a ticking or chuffing noise, can bring on a check engine light, and may even knock fuel economy or low-end torque around.

• Common signs a gasket’s on the way out: sharp ticking on cold start, exhaust smell under the car or in the cabin, black soot around a joint, raspy note under load, and occasional CELs such as P0420 due to false readings.
• Good replacement practice: pre-soak rusty hardware, support the exhaust so it’s not hanging on studs, clean mating faces, fit quality OEM-equivalent gaskets, and tighten evenly to the torque values in the Subaru FSM. Use new spring bolts and nuts at the donut joint, and recheck for leaks after a heat cycle.

For Aussie and Kiwi conditions—coastal air, road spray and the odd gravel road—give the underbody a periodic look. If the Impreza has scraped a speed bump or been used for beach runs, it’s worth checking the front pipe donut and flange gaskets sooner rather than later. Gaskets themselves are inexpensive, most of the cost is in labour, which varies from a quick half-hour for an accessible flange gasket to longer if studs are corroded or the manifold needs removal.

Popular questions about 2016 Subaru Impreza exhaust gaskets

Does the 2016 Impreza use a donut gasket?
Yes. The FB20-powered Impreza uses a spring-loaded joint with a ring (donut) gasket between the front pipe and the next section. It allows a bit of flex while maintaining a gas-tight seal. Replace it any time that joint is undone or if there’s a leak or rattle.

Can an exhaust leak cause a check engine light?
It can. A leak near the front oxygen sensor can skew readings, leading to lean/rich corrections and codes like P0420. Fixing the leak and clearing the codes usually restores normal operation if the sensors and cat are healthy.

Should exhaust gaskets be reused?
Best practice is not to. Subaru’s service guidance is to fit new gaskets on reassembly. Reusing old gaskets risks leaks, noise and do-overs, especially at the manifold and donut joints.