I have a HX civic coupe and want to do a header back exhaust on it.
I have the dc stainless 2-piece header for a civic ex, a 2.25 high flow catco cat that i'm gonna have flanged and an o2 sensor bung put on, and the aem cat back exhaust. I went to get the cat welded today and the guy at the shop said moving my o2 sensors from where they are now (on top of the header and after my pre-cat) to at the end of the dc header and after the cat would mess up my air/fuel and my car would get horrible gas mileage, etc. Is this true? If so should I get a A/F gauge and a VAFC in order to make sure the ratio is good or do I hot have to do this? Please help me with this problem. Thanks.
Jesse

 

if the parts are for your car the o2 sensors should not have moved... as for your solutions? I dunno I'd get the parts that would leave them where they are supposed to be...

 

anyone have any experience with the moving of an o2 sensor on their exhaust?