2002 nissan sentra se r making loud muffler sound from the front end

SOURCE: Alero loud humming/roaring sound coming from front end.

That's indicative of a wheel bearing, which is why you were told to change that out. However, it's also possible that the carrier bearings in the differential (where the drive axles attach) have gone bad. That happened to me on my 300ZX several years ago, and I had to replace the diff bearings. I would have them checked out somewhere other than a dealer (you'll probably get a better price from an independent shop).

As a sidenote, to be sure it wasn't a wheel bearing, if you hear it quiet down in a turn one way but get louder in a turn the opposite way, it's likely the wheel bearing. If you turn left at speed and it gets louder, then it's the right bearing (since you're loading up that side of the car). If it gets quieter in a right turn, it's the right side (you're unloading that side of the car and not putting as much weight on it, so it doesn't drag as badly). See if you get that symptom just to be sure that the wrong side front wheel bearing wasn't changed.

SOURCE: HOW DO I CHANGE THE

you will have to take the whole front of the motor apart. it should be alot easier to go through the fender well to do this.

SOURCE: Loud clunking noise in front end over bumps

THIS IS THE REAR CONTROL ARM BUSHINGS THE BANGING IS THE CONTROL ARM HITTING THE K FRAME

SOURCE: 2002 nissan sentra gxe...1.8ltr trying to replace

Here is a diagram of the 1.8 exhaust from the service manual, you can obtain a full factory service manual for relatively cheap from Promanuals.net here.

SOURCE: How to replace cabin air filter nissan sentra

lOOK BEHIND THE GLOVE COMPARTMENT. Compartmet is probabily plastic and all you have to do is push in real hard to get them past dash board.