Parts for your 2009 Mitsubishi Lancer-Exhaust gasket

2009 Mitsubishi Lancer exhaust gasket: what it does, why it matters, and when to replace it

Based on technical references including the Mitsubishi Lancer (CJ) Workshop Manual (2008–2010, Group 15A – Exhaust System) and the Mitsubishi ASA electronic parts catalogue for CJ models, the 2009 Mitsubishi Lancer is built with several exhaust gaskets. These are specified at the exhaust manifold-to-cylinder head, manifold/front pipe junction (donut/crush ring), and various flange joints through the mid and rear sections. The workshop manual calls for replacing these gaskets whenever the joint is disturbed, confirming they’re fitted and service-relevant on this model (including 4B11/4B12 and turbo variants like Ralliart/Evo X).

The exhaust gasket’s job is simple but critical: it seals hot gases at each joint so there’s no leaks, no raspy ticks on cold start, and no stray fumes creeping into the cabin. Proper sealing keeps oxygen sensor readings honest, which helps fuel trims and emissions, and it preserves the intended exhaust back-pressure. On turbo Lancers, fresh gaskets are even more important for spool and boost control.

On a 2009 Lancer you’ll typically find: a multi‑layer steel manifold gasket at the head, a metal/graphite donut between the manifold (or turbo/downpipe) and the front pipe, and flat gaskets at flange joins further back. There’s no strict time-based interval for these, but they should be replaced any time the joint is undone, or if there are signs of leakage like a ticking sound on acceleration, soot at a flange, whiffs of exhaust under the bonnet, or a P0420 catalyst efficiency fault after a known leak. A quick check during servicing is smart—look and listen around the manifold area and front pipe, especially after a long trip.

When replacing, work on a cold system, support the car safely, and follow factory torque specs and tightening patterns. Spring bolts at the donut joint should move freely, if they’re seized or the springs are collapsed, fit new hardware. On turbo models, always use new gaskets at the turbo outlet and downpipe. A light, high-temp anti-seize on the studs and nuts (as permitted by the manual) helps the next service. Quality gaskets from reputable brands or OE-spec parts are worth it, they seal better and last longer, which keeps the Lancer quiet, safe, and WOF/roadworthy-friendly.

• Common signs it’s time: ticking on cold start, exhaust smell, soot marks, poorer fuel economy, or CEL related to O2/catalyst after an exhaust repair.
• Best practice: replace gaskets whenever an exhaust joint is opened, recheck fasteners after a couple of heat cycles.

Popular questions about 2009 Mitsubishi Lancer exhaust gaskets

Where are the exhaust gaskets on a 2009 Lancer?
They’re at the key join points: the exhaust manifold to the cylinder head, the manifold or turbo outlet to the front pipe (a donut/crush ring), and flat flange gaskets through the centre and rear sections. Turbo models add metal gaskets at the turbo-to-downpipe and sometimes at the cat connections.

How often should the exhaust gaskets be replaced?
There’s no set kilometre interval. Replace them whenever an exhaust joint is disturbed or if there’s a leak. On higher‑kilometre cars, or where hardware has rusted, it’s good practice to fit new gaskets and spring bolts to avoid repeat leaks.

Is it safe to drive with a leaking exhaust gasket?
Short trips might be possible, but it’s not ideal. Leaks can let fumes into the cabin, create excess noise, affect oxygen sensor readings, and potentially trigger emissions faults. For safety and to keep it roadworthy, get the leak fixed promptly.