Direct injection engines can suffer from deposits on the backside of the intake valves. On older engines, these were washed off by the fuel spray - but not anymore. This is particularly a problem with boosted engines as they tend to have more oil vapor in the crankcase. The stock PCV system burns this off by feeding it into the intake air, which increases the buildup on the intake valves. To make matters worse, the usual gas additives that clean off your valves don't work becuase fuel never gets to the buildup.
We worked with Verus Engineering to test their newest air/oil separator. This device supplements the stock PCV setup. It collects the air from the crankcase and the head. It's run through a separate 5 micron filter for each source, then the air passes through a series of baffles and stainless mesh. Two more 5 micron filters give the air one final scrub before it heads for the intake manifold and intake piping. The extracted oil is captured by the separator and can be easily drained with a turn of the drain valve. This allows you to monitor the level of oil vapor in the engine, which is an indicator of engine health. It also includes a forced-induction compatible PCV valve which can cope with positive intake manifold pressure.
We have tested this on track with one of our turbo NDs, and it works well. Naturally, it's made of 6061-T6 aluminum and anodized black for long life.
If your car is equipped with a sound tube, you will need a sound tube delete. Otherwise, everything you need is included.
Note: Mazda changed the ECU mounting bracket for 2019. You will have to make some small modifications to the air/oil separator bracket.