I have a 98 1.6 civic, just an intake. I would like to install a 2 1/4" exhaust with flowmaster 60 series. Should I stay with the cat back or install a header too? I did not want to interfere with taking the cat converter out and throwing off 02 sensors, making excessive fumes. I know you also still want some restriction

 

Here is a post with some general information. https://www.hondacivicforum.com/foru...ad.php?t=44556

Here is what I would do if it was me https://www.hondacivicforum.com/foru...ad.php?t=73237

Bottom line is what do you want to do? Enjoy......