im gonna buy me some hi flow cats but a couple questions that might sound stupid.... do i need a chip for them and and cats should i get if i have flowmasters and if it doesn't matter then what is a good cat to get thanks for the help

 

No chip needed.

I got my cats on eBay through some vendor blowing out a bunch of them - Do a search on there for "CarSound" cats. They're the same as Magnaflow, just not a pretty polished outside.