What should be here?

[Joe#]

I've just been doing a few little things under the bonnet and had the usual visual check of everything. And I noticed the there was a threaded hole that wasn't being used. It's at the rear left hand side of the engine, right next to the air on pipes.

Quick picture.

Thanks.

 

[ekaJ]

Dunno but mines the same mate.

 

[Joe#]

I had a look on a mates 172 before and he didn't have a threaded hole at all. So it can't be very important.

 

[Joe#]

It could be where some sort of clip should be, that helps to support the pipe that runs to the carbon canister maybe?