Honda SM4 Intake Manifold Gasket

For some Honda old model like SM4, SV4, CRV which using the F20A, F22A, B20A engine, you may noted that their intake manifold gasket may have one of the whole, is strengthen with the o-ring seal.

There must be some reason why they need to design a o-ring seal at that area, but to include the high quality seal on this area, this gasket cost will be much higher compare to those without it, so you may found those local manufacturer making the gasket without the seal.