sorry for posting on an oldie - but I could not imagine HOW can someone use RTV silicone on a reused headgasket - RTV silicone is very slippery and does not compress, it will literally shred under the head pressure, Hylomar is supposed to be used on the fire ring periphery of the head gasket.
On the other hand the exhaust manifold is from a PR3 (B16 OBD-0) engine that has 2 O2 sensors - the P30 engine uses a 4 wire O2 sensor on the collector after the header