I put a MAF adapter on my 98 legacy 2.5 gt and a K&N filter. I started the car and there is this crazy drone coming from it that sounds like a vacumn cleaner. I tried moving things and doing everything short of shortening the intake length. If you remove the filter and the MAF adapter the car still makes the same sound. The car runs noticeably different.. not faster just seams to idle smoother and rev a little easier. but this drone at a stoplight or any other time the car is idling is pretty loud. any ideas or suggestions..

 

for all those musically inclined the note it produces is a slightly flat B. i checked it with my guitar tuner..

Remove the muffler and run straight pipe, you won't notice the drone, whether it's b flat or b sharp...

You know all that plastic crap including the air box you pulled out? A fair bit of that is referred to as the intake silencer, and it "silences" the intake noise. Some people, including me, think intake noise sounds cool. Others, excluding me, think exhaust noise sounds cool. Whatever your preference, you modify the silencing system that pertains to that noise. You now have a car that sings to you in B. So B happy.

it sounds like the humming of a vacumn cleaner. would replacing that plastic intake tubing back to the air box by the throttle body help at all?

it sounds like the humming of a vacumn cleaner. would replacing that plastic intake tubing back to the air box by the throttle body help at all?

 

Yes. Removing the big plastic "tube" that goes in the fender is the only "mod" I have done to my 98 and it makes the nasty (I'm one that doesn't like it) drone noise at idle. When you nail the gas pedal it makes a much deeper exhaust noise though.

My intake does that when I open the air filter housing just a tiny crack. When I open the housing the whole way, the drone goes away, and the intake makes nice sounds.

Sounds to me like your air intake has a small leak somewhere. I would get out the stethoscope and try to locate the source of the sound.