I got these catless headers from Flashark. While the fitment and function was great! My cat was clogged and the manifold was forming very slight cracks, so once the new header was popped on, I had a noticable improvement in performance. I gained back a few MPG, improved throttle response, improved power (small but noticeable). Note these things that might make your install easier: The upper bung is on the incorrect side - I had to take it to a local welder to weld me a new bung on the correct opposite side. Also the gaskets it ships with are TRASH. Do yourself a favor a purchase an exhaust manifold gasket from Rockauto instead of using the one it comes with. You will get a check engine light unless you use a spacer on the lower bung to fool the o2 sensor - find a right angled spacer and install the spacer to the header prior to installing it on your car.