I posted this on the 964 Turbo forum but was curious if anyone knows why the plumbing in my car is different from the manual.

I removed the IC and found that I had of all things an Oil cap used to plug a vent pipe from the Air filter assembly.(red Cap) It was falling off and was sucking in air. I clamped it down and it made quite a change in the overall performance of the car. The torque feels stronger and boost comes on much faster. In the past at 0 boost I would punch it and the gage would read 0.0, 0.2, 0.4 etc up to full boost. Now it just goes from 0.0 to 0.4 to fullboost with virtually no lag, all in the amount of time it took to go from 0.0 to 0.4 before. The car feels much faster to the point it is scarry.

What I was curious to know is this. The manuals show no connection from the red cap (air cleaner) to anywhere in the system. Is this correct? It also shows the connection from the left of center on the vacuum limiter to the IC. Instead my IC is plugged and the connection attaches to the plastic pipe directly below. This is the same pipe the BOV connects to. Why would this be done?

Does anyone know if this is correct and if not why it was changed? Also would an air leak in the air cleaner side cause such drastic change in the performance of the car?

Any help would be appreciated.

PS sorry I cannot post the pic it is located on the 964 T forum titled Whats going on here?