hi,i have a 5vy engine which has what the parts list calls air induction system fitted,its plumbed in to the top of the cam cover.what does it do?can i do without it?
thanks

You don't need it for the engine to run. The hoses can be blanked off, or a pair of blanking plates made up to seal off the head

From the manual:
The air induction system burns unburned
exhaust gases by injecting fresh air (second-
ary air) into the exhaust port, reducing the
emission of hydrocarbons.
When there is negative pressure at the
exhaust port, the reed valve opens, allowing
secondary air to flow into the exhaust port. The
required temperature for burning the unburned
exhaust gases is approximately 600 to 700 °C.

I can't speak for whether you will need it for your emissions testing or not though

thanks for that,i'll blank it off as this is a rebuild so no worries about emissions

Why take it off if it reduces emmissions?

I removed it because a) it is something else to go wrong, but more importantly b) because it stuck up too high in the way of my hood. (mine is a FJR1300 so may not be the case in the R1)