I have a 2002 VW Jetta wagon with 76500 miles and it started rattling at the light and now everytime I stop it rattles. one mech said I needed a new cat another said it was the heat shield and as such was not biggie just remove it but to me that sounded iffy? I don’t know what a heat shield is… the car is a champ and has wonderful get up and go so help.
I am not in favor of removing the heat shield,removing the shield is quick the customer is happy (no noise) and shop doesn’t need to charge you because the activity took so little time,the mechanics a hero and every bodys happy. The trouble is you have lost the protection the shield offered. Be willing to pay at most .5hr labor to get the shield correctly secured.
With the shield secured it should be no trouble deciding if it was the cause of the rattle or the cat,cats do rattle.
If the shield that was rattling is also the shield that is on the cat and the cat does end up being the source of the rattle get your nechanic to apply the money spent securing the shield to the labor to fit the new cat. This is the area where you will have to use some skill negotiating.
Lastly make sure that your entire repair (rattling cat,not rattling shield) is covered under the Fed 8yr/80000 mile warranty on cats. You will need a Dealer to perform the work if you do qualify for the Fed. warranty.
I agree with oldschool about not removing the heat shield (if that turns out to be the source of the rattle) however the standard “fix” im my neck of the woods is to secure it with a large worm-type hose clamp for about $3 at the hardware store. It’s a fix that will outlast the converter.