Just the other day, I was stopped at a redlight and I noticed a rattling noise from under my car. When I put it in neutral, ( I drive an autotragic) the noise stopped. I searched the threads, and I saw that it could be from the exhaust hitting the gas tank. The Y-pipe that I have has been in for a couple years, so I don't think that it would just all of a sudden loosen up. Is there any possibility that things could be "loosening up" from the bass from my car stereo?
And also, what would be the quickest, most affordable fix to this annoyance. I've been saving to get a catback system in a couple months, and I would really like to have the issue figured out before then. Feedback from y'all motorheads would be awesome! Thanx!

 

If it is the exhaust rattling, then get under the car and tighten it up, replace any worn hangars, etc.

 

your questions are not in chronological order:

You cant know how much something will cost to fix until you actually FIND the problem...

its the exhaust hanger thats broken off, after the resonator you will see a metal bar preventing the pipes from hitting the asphalt, there is a hanger at that section of the b pipe that broke off on mine and caused it to rattle the exact same way you are describing...take it to an exhaust/muffler shop and enjoy the sparks

 

I noticed on mine that there are a couple of end pieces on the cat that are spot welded and the mechanic that noticed it said it's pretty common for those to come off. I would check there first.

 

hangers probably broke or metal inserts into them rusted off +1 for exhaust shop

 

check your exahust or check near the rear o2 sensor n look on the passengers side i had a little plate cover rattling there...

 

Checked the plate on the passenger side. Fixed it! Glad I didn't go to the muffler shop or I would've been out about fifty bucks... Thanks a ton for the pointers. God Bless the .org!!! You guys have saved my butt more than a few times! Keep on keepin' on, bros!