Hi All, I will be getting a tune next month for my 03 BA, Fitting 42lb injectors, HDI intercooler, XCal 3 and new plugs and hoping for around the 250-270rwkw. I don't really want to replace my Valve springs but have read that fitting a cat can help with valve float. (Has the rear muffler removed also) Can anyone tell me if this cat is any good or have any other advice. http://www.ebay.com.au/itm/3-BOKKA-High-Flow-Metal-Cat-XR6-WRX-Turbo-VL-Skyline-/230598380535?pt=AU_Car_Parts_Accessories&hash=item35b0bc0bf7 Car is a BA 1 with a 4 speed auto with 80000km on the clock. Thanks