I recently installed a header on Saturday, although the 2nd peice that connects to the cat was a tight fight and didn't line up well. I then managed to get the 2 peices together, the next day when I was driving home from work, the 2 peices seperated and my car sounded horrible because of it not being connected. I then took it to a muffler shop to have them fix it, because I had no time with my new job. Today, driving home from work, the 2 peices are connected, but it sounds like I have a bad exhaust leak.

What do I do? How do I get it to sound normal again?

 

Maybe the header-to-head seal is not good enough. Did you get all of the old gasket off of the head and header? And then get a new gasket? This is something that I might suspect.

-Shane

 

that kind of header is it. oem?
look for areas with black soot or dirt like at the o2 bung and such. if it leaks where it bolts up to the head you will see black burn marks on the head where it is leaking i had it when i just bolted my stock header using the old gasket.

 

Also, is it a 4-2-1 or 4-1 design? And did you buy it new or used?

 

The header is brand new, it is a 4-2-1, I used a brand new gasket for both the top peice and inbetween the first and 2nd peice. The part that connects to the cat, I used my OEM donut thing that came with it, and I only have an o2 sensor on the exhaust manifold itself, not one by my cat. The thing is, I took it to a MUFFLER shop yesterday and they failed at fixing it, what can I do now? It's really annoying and ugly sounding.

 

what brand is it? sounds like an ebay special

 

You know it. Could that be the problem? It's an OBX R, they sell some of OBX parts around at local shops here... So I was assuming it was a so-so brand.