I have a 99.5 New Jetta GLS, 2.0 cyl, automatic with 84,000 miles. There is a rattle underneath and the mechanic told me I need a new catalytic converter. He said the part and labor would be $700 (approx $500 for the part). I have done some research and I see I can buy a part for $80 which can be welded in or a new part which includes the pipes for about $300. How would I determine if I should buy the $300 part and is it worth it? Thanks you.