I found its home, YAY! ?, there was a very small outlet stub under the inlet manifold nearest to the radiator. It was tricky to see as it was hiding and fairly small.
I replaced the pipe with some new silicon hose I had kicking about.
The test drive revealed a little of the missing power thats been missing , I suspect the coolant temp sender will reveal the rest.
Yeah daft me told you where it was on plastic manifold.