I’ve been doing weeks of research but haven’t found an answer that satisfies me. Some say yes others say no but do not elaborate on the matter. I live in Los Angeles California as we all know California is not mod friendly I want to buy a header for my Ek but I want to keep my catalytic converter and install a cat back after but I want to know what header I could buy to keep my cat or do I need to remove the catalytic converter?

 

Since you likely don't have an EK chassis anyway, can you refer to your car in American terms? It makes a difference and "EK" tells us nothing useful to help you. Is it an Si, EX, LX, HX, DX, or CX? Does it have the stock engine, or have you swapped something else in?

 

Its a 1998 Civic Ex coupe engine was swapped to a D16A but it’s stock. It’s 5 speed manual I put a short ram that’s about it.

 

Gotcha, that's helpful. You can put a CARB approved header and a California compliant cat for a Civic EX on it, and that will all bolt up to a cat back designed for an 2dr/4dr Si/EX Civic. The only issue you will have at that point is if the smog guy notices you don't have the original D16Y8 in there, but if you have the Y8 intake manifold and the emissions equipment is all hooked up with no CELs, then I'd be willing to wager a six pack that they won't care. Good luck.

 

The car does not have the Y8 manifold on it it has the D16A one I believe but the car passed smog with no flying colors is the Y8 intake better by any chance? And no CEL lights on thank god