Ford Repair: My 96 Chrysler v6 hardtop Sebring engine is roaring., chrysler v6, oxygen sensors

Question
For awhile now my engine has been making a loud noise. It's not knocking or nothing, its roaring especially if you accelarate. Honestly, I don't know if its the engine or not but the noise is irritating, you can't even hear yourself think. Can anybody tell me what this might be?

Also, I need some O2 sensors replaced. What are they and what importance are they to the vehicle?

Please help!
Thanks!

Answer
first your in a ford forum-

but as for the noise it could be something as simple as a pulley bearing or maybe a bad compressor bearing or alternator-could be a transmission problem-
as far as oxygen sensors how do you know if someone just scanned it with a code reader say at an autozone or advance and got o2 codes that does not mean they are bad and if they are what caused it they do go bad but a lot of times there is an underlying cause and if replaced without repairing the cause they will just go bad again. as far as importance your vehicle uses the readings from these to help adjust fuel mixture so it burns fuel efficiently if these are bad it may casue a myriad of driveability problems such as poor fuel mileage-possible rough idle-surge even a stall under right conditions

do you have a reputable garage someone you can trust i am not talking about your next door neighbor or hair stylist i mean a real garage someone your neighbor or hair stylist would use for their car problems if you don't have someone like this ask around find one and have your vehicle checked out-you may not like what they tell you but it may help your car last longer your noise may not be much but it may be a serious thing also so find someone to check it out.
good luck.