I too agree that fitting an aftermarket airfilter is a waste of time and money. The stock one has had thousands of dollars thrown at it in order to achieve the best mix of flow vs protection. why screw with it?

Same goes with the exhaust. Unless you remove cats, polish and flow the head, modify the intake and re-tune the injection to suit, you are wasting your time.

In the modern dirt bike scene, almost everybody puts an aftermarket exhaust on their bike. Why? Did yamaha purposly put an over-restricted exhaust on their motorcross bike so that it sufferes in the horsepower stakes? Yeah right. What they did do is spend millions of dollars designing an intake, combustion and exhaust package that compiment each other. Change one on its own and you destroy the harmony.

When the exhaust on a bike is replaced and the dyno says more power, there is more power. BUT, where is the power being made now? Usually what is created is a razor thin power band of good increased peak power but because it is in such a small rev range it can be almost impossible to use to it's full potential. The original stuff was designed to win races! Of course, it is a bit different if the exhaust was designed to meet noise emission regulations. Then the engine can usually benifit from a re-jetting and freer flowinf exhaust.

I would imagine that the oil in the filter has damaged the MAF rather that dust particles.
If you want to go fast, buy a $5000 sports bike with a litre engine and flatten Enzo's!! Then go cruising in your benz.

__________________
Andrew
300e 294,000mi
380sel 185,998mi
380se 309,980mi