I have an 05 350z and its throwing a cel for my cats, I bought the car with a magnaflow H pipe already on it. I want to get hi flow cats after talking with the autozone guy, but he said I'll have to get the oem cats cut and hi flows welded back in. However, magnaflow's High flow Cats claim to be a direct fit, does anyone have experience with hi flow cat installs? give me a little insight

 

get a reputable brand and they will be direct bolt ons

 

same what travlee kind of said, its hard getting CARB legal cat here in California or NYC, most people either get straight bolt on high flow cats that are able too pass emissions or go to a muffle shop and have them weld on a universal catalytic converter( which i dont recommend since there welds are crap, some stocks stick or oxy weld it and not properly mig or tig weld). hope that helps man. Good luck

 

OP I don't know if you have emissions to worry about or any kind of visual inspection. The cheaper better performing option is Test Pipes (Aftermarket down pipes with resonators prefefably) Louder than stock, depending on muffler setup won't get you pulled over and will definitely help the car breathe.

People who haven't tested cat-less cars are afraid ahead of time of sound being to loud. The muffler/mufflers setup is the key to it all.

I had a modular Mustang that came with 4 cats, removed the 4 cats with a straight x-pipe and 2 chamber flowmasters than to a magnaflow catback and it was loud but the usual mustang loud. Nothing that ever got me pulled over in a 200k population city. I than switched to a catted x-pipe with magnaflow magnapacks (straight thru muffler) The catted x-pipe car was much much louder than the version without cats. Just an FYI