I am thinking about putting a header on my civic cx 1.6 non vtec. I was wondering if i do this, will it pass inspection and emission? I have a check engine light that is throwing a p0420 which is either a o2 sensor or a bad cat. That is why i wanna switch to a new manifold or a header.....

 

as long as the header is ment for that motor you should be fine for inspection...
umm you might want to check more on the O2 sensor as that could eventually if it hasnt already make ur engine run like crap...

 

if u wanna put a header on a cx ur goign to have to rewire ur secondary o2 sensor to make it reach the second o2 sensor on the down pipe...