I use the free flow cat from ZZ performance, I think it'* about $70, getting it installed will depend on the shop, but $100 or so can be expected. If your car is a 2000+ you wont be able to use that cat. Purplehaizer has a link to the one you will need then.
You wont gain any HP, but can get back what was lost over time due to restricted flow. If your old cat is bad you may feel a bit of a difference. Likely you will here a difference though. The tone will go a little deeper.
As for removing the cat, not a good idea. You will trip SES lights and fail emision inspections.
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1997,1998,2000,2005 year confused Bonneville SSExi. Stock? ish.
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