Cometic K20C1/K20C4 Turbo Exhaust Gasket for Civic Type R

Cometic K20C1/K20C4 MLS Exhaust/Turbo Gasket - Part #C14022-020

The K20C1 in the FK8 Civic Type R and the K20C4 in the 2.0T Accord and RDX don't have a separate exhaust manifold. The runners are cast into the cylinder head and the turbo bolts straight to one oval flange on the back of it. That single joint takes every bit of heat and pressure the engine makes, and when the factory gasket gives up you get ticking on cold start, exhaust smell in the cabin, and boost that never quite hits target. Cometic's C14022-020 is the MLS replacement for that turbo-to-head flange, and it's the gasket to have on the bench any time the turbo comes off a K20C1.

What It Is and Why It Works

This is a .020 inch multi-layer steel gasket cut for the K20C1's oval turbo inlet port, which Cometic lists at 3.26 by 1.66 inches. An MLS exhaust gasket works the same way an MLS head gasket does: embossed stainless layers spring back with every heat cycle and hold their torque set instead of crushing flat and burning through the way a fiber or graphite gasket does on a turbo flange. It seals the aluminum head to the cast turbine housing without any sealant, and it comes off clean if the turbo has to come back out. Cometic released this part for the 2017-2020 Civic Type R. The K20C4 in the Accord 2.0T and RDX uses the same head casting and turbo flange, which is why Cometic's dealers list those too. Use it for a turbo kit that bolts to the stock flange, for reinstalling the factory turbo after a coolant line or heat shield repair, or as a fresh seal on a tuned FK8 that's started weeping under higher boost.

Specs

Fitment

Cometic's own application chart names the 2017-2019 Civic; the Accord 2.0T and RDX applications come from Cometic's distributors. The 2021 FK8, later Accord 2.0T, the TLX 2.0T, and the FL5 Type R share this head-to-turbo flange but are not on Cometic's chart, so check your flange before ordering for one of those.

What to Know Before You Buy

This gasket seals the turbo to the head and nothing else. The turbine outlet to downpipe joint uses its own gasket, so if the downpipe is coming off too, get that one at the same time. MLS only seals against flat surfaces. If the old gasket blew out on a tuned car, lay a straightedge across the turbo inlet flange before you bolt it back up, because a flange that's warped from heat will chew through a new gasket just as fast. Install it dry with no sealant, torque the flange nuts in sequence to factory spec, and replace any nut that fights you on the way off; these live in the hottest spot on the engine and don't take kindly to being reused three times. Cometic builds these to order, so if the turbo is coming off next month, order the gasket now.