Why is a loud sound coming from under the car near the front

Possible wheel bearing that is worn. Have the bearings inspected.

Belt may be slipping. Try some belt dressing.

sounds like a c.v. axle is bad.

could be a bad tension pulley or just the belt needs belt dressing.

Have the exhaust system inspected.

I could be more helpful if you would be more specific. Is it a front-wheel drive? Is it a squeaking or thumping sound?

Check your cyalytic converter and your entire exhaust system for damage. A blocked up exhaust will give you a loss of ower as will a clogged or damaged cat con.

Your cadaletic converter is clogged.You need to get a new one.

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.

Same problem with an LS...wheel bearings. Comes in the whole hub assembly. Just had it fixed for $340.