Here are some pictures of mine, not very clear but may assist you.
The lower hose from the filter box under the Maf electrical connector runs to the secondary air pump which has been removed from yours, just blank the vacant hole in the filter box with some good tape to seal it. The intake bellows fitted after the Maf fits to the throttle body, put your new one on when you get it and secure the jubilee clips to seal it.
The ribbed plastic pipe is the one blanked with the bolt on yours, fit the blanking plate
@t-tony is sending you and remove the pipe and the silver coloured valve unit, they are redundant.
The pipe branching off the intake bellows is plugged in using a plastic connector, the hose then makes its way under the intake manifold and connects underneath, its a faff to get to that end, may need to lift the manifold up to get to it by undoing its retaining bolts/nuts. Clearer view of the secondary air pump in this picture that you no longer have on yours.
Closer view of the hose on the intake bellows plastic connector for the hose going under the intake manifold.
The hose at bottom right of picture connected to the manifold leads to the brake servo on the bulkhead the hose runs along the plastic channel at the back of the engine bay. The hose connected to the round crankcase ventilation valve runs to the rocker cover and feeds oily fumes from there back to the round valve.
Also check all the small thin hoses at the front of the engine for cracks or leaks, you should be able to get suitable sized pipe at motor factors locally if any need replacing, they sell it by the metre. Also worth checking at the back of the intake manifold for any rubber blanking plugs that seal off connections that are not used, these perish and fall off allowing air to get in. Can't remember if there are any of these on the 1.9 but they are on the 2.2 and 2.5 models.
Hope that assists, far easier to have hands on with it in front of you to suss it out than describe it all.
