Open sensor outlet on the intake?

[(TDS)Apocalypse]

Hello all, I have an 89 hatch w/ the 91 KA in it (previous owner's mods). During the filter change after I bought the vehicle I noticed that the intake pipe leading from the air filter has an open little side outlet that nothing seems to go into. The outlet is just to the left of the radiator (looking into the engine bay) and It's driving me nuts cause I'm pretty sure I'm losing intake power through it. I already located the MAF but the IAT seems to be a possibility except the engine runs well enough in cold weather (40 and below). I did hear though that on the 90 and up KA's Nissan incorporated the MAF & IAT functions into one sensor so I am well and truly confused. Any enlightenment on this subject would be greatly appreciated.

[niznos]

As far as I know, 89-90 had IAT and 91-94 did not. You got a 91 engine in a 89, so the engine swapper probably used the 89 AF housing with the 91 engine. As long as the IAT hole is before the filter it will be okay, but if it is after, then you need to plug it so dirty air is not getting in.

[Dattebayo]

The hole is probably for the AIV, which was removed maybe. Its not important to your purposes.

Tell me, under your hood, is there a black plastic box to the right of your engine sort of hovering there? It's cube-like with rounded edges. If not, then thats where the pipe from that hole used to go. I think it is for the PAIR valve which turns on the device.

No matter if its before or after the air sensor, you should plug it with something solid. Go to your hardware store and look for a PVC pipe end cap (in the plumbing section) that might fit it