OK, so I took in the ol' Elantra to a muffler shop. They lifted it up and found that a component on the converter assembly is corroded, and since it is OEM, they really can't touch it, it is Hyundai's baby. It is not just one little piece that can be replaced, but the entire component has to be replaced, no mix and match. Everything else is still bright and shiny, but this one part is severely rusted.

I've an appointment with my Hyundai dealer on Wednesday, but something tells me this is gonna hurt my wallet.

 

May cost you nothing. My Sonata has a 80K/8 year warrenty on Federal emission equipment. The catalytic converter is specifically listed as a covered item. I think this warrenty is applied across the entire Hyundai product line in the US. Goto:

http://www.hyundaiusa.com/global/warranty/warranty.aspx

to read the specifics. Since this is a Hyundai-source only item, I am guessing it is covered unless the car is older than 8 years (which it isn't) or has more than 80K on the odometer.

Good luck.

P.S. There is a seperate "California" emissions warrenty that provides additional coverage in 4 or 5 other states. You may live in one of those states. The parts coverage apparently varies by Hyundai model.