What is a silencer?

The 'silencer' is a small circle of zig-zag cardboard inside the back of the air can, behind the 1G mass airflow sensor (MAS). It is not part of the MAS, and appears to have no function other than to quiet things down a bit - in fact, 2Gs have no silencer. It is not the gold honeycomb, which is part of the MAS itself (on the front), so be sure you get the right part.

As for removal, having a shop manual handy makes everything a lot easier.

Performance gains for removing the silencer itself should be expected to be nil; it is not that restrictive. It may provide a slight performance gain when combined with other mods, however, and the removal is simple, making it the first ever 'free mod' for DSMs. It also provides an excellent starting point for newbies who need to learn more about their cars; there is incentive (performance), economy (free) and a difficulty level ideal for non-mechanics (very easy), yet provides a great deal of basic information about the car.