Rep Power: 0

i have a 2005 civic ex coupe everything is fine but i noticed my headers are really rusty i want to change them but i need something that will be street legal i also want to change the catalytic converter and exhaust... i was thinking magnaflow but idk if the whole thing will play out properly because i dont want a check engine light... i need help in what parts to buy to change everything from the headers down to the exhaust...
if you find this question to be stupid im sorry i just never really took my time out to learn about cars i admit im a newbie at this which is why im asking for help...

 
Rep Power: 291

Pretty much all headers are not road legal, with maybe the exception of DC Sport header.
All high flow cats will give you a CEL.
If you live in an emissions state like Cali or NY, any of which will not pass emissions.

 
Rep Power: 511

random tech's won't throw a CEL. If all else fails, and you don't live in a state that requires a visual inspection every time you get a smog check, a mechanical O2 simulator works well.

Also, moved to the right forum.