Can't remember if port is for a plug or sensor

[f575gtc]

Hello all,

I am replacing a 4.3L mercruiser on my 2004 Maxum and on the front of the engine intake manifold there is a threaded port on the starboard side of the boat that I don't know if is just for a threaded plug or a sensor. Unfortunately I had "help" taking the old engine apart and before I could document where everything was, the port was open.

The picture shows what I am talking about.

https://ibb.co/fVpRfk

Thanks a bunch guys!!!

 

[bman440440]

plug

 

[Bondo]

Ayuh,.... That's a drain plug for winterizin' it,...