After diagnosing a bad IACV valve on my 1999 Honda Civic LX, I replaced it with a new aftermarket one. Problem is, I am still getting vacuum leaks around the outside of the valve despite torquing properly. I tried another IACV from another part store with the same results. Gaskets are new. Not sure what I am doing wrong. Someone on another forum suggested rtv in addition to the new gasket, but I don't think this is wise. Any help is appreciated. Thanks.