Was going to install a new header on my car and took off the heat shield and saw this. I don't think it is stock but I am not sure, does anyone have any idea what one it could be?

Thanks

 

Looks like one of the obx set ups. Can usually tell brand better by connection type down below.

http://www.sparktecmotorsports.com/obx-857.html?utm_source=googlepepla&utm_medium=adwords &id=91571116997&gclid=CMmA9KDikcACFQYGaQoddIUAC g

 

Here are some of the underside images, looking underneath it looks more like a stock unit.

 

Looks stock to me.

Nik

 

The OBX doesn't come with a cat, so often, a stock cat is affixed to it.

 

that is a stock header. color and shape of runners, and the pre-cat is a dead give away

 

you can typically see the flex joint and collector section from the top. I don't see that in the first pic and the under side pics aren't very clear.

 

Who did you get the car from, private sale or dealer ? I have a Mynes header that has the OEM cat fabricated to it, so don't rule it out as a stock until you can get more info, or take it off to get a better look at it, one of the runners in your first pic looks a little shiny which leads me to say you need a little more info before calling it stock, you just never see a stock manifold on a R53 with a shine to it.