HS05SW1HDR. Fitment Information: This high - quality Invidia header fits 2004 - 2021 Subaru WRX STi, 2006 - 2014 Subaru Impreza WRX, and 2002 - 2005 Subaru Impreza WRX (must have 2.5L oil pan). Features: It comes with equal length runners, is made of 304 stainless steel, has a 2 - bolt style up pipe, and 1.65 - inch diameter runners. This Invidia header is a great bolt - on upgrade for those aiming for a Full Bolt - On (FBO) setup. Switching from the factory unequal length manifold to this equal length stainless - steel header will boost power and look much cooler than the stock cast manifold. Keep an eye on Cylinder 4!
Using this Invidia header is straightforward. Just bolt it on as an upgrade to your existing manifold. For it to fit the 2002 - 2005 Subaru Impreza WRX, make sure your vehicle has a 2.5L oil pan. As for maintenance, since it's made of 304 stainless steel, it's quite durable. But it's a good idea to regularly check the bolts to ensure they're tight and there are no signs of loosening. When you notice a decrease in performance, it might be time to inspect the runners for any blockages or damage. Also, remember that when making this change, keep an eye on Cylinder 4 as it can be affected by the new setup.
