installed corksport turbo back system a lot of hp gains feels like to me on stock boost the only problem i have ran into is that with the s pipe installed my car seems to run way lean now. i have actually thrown a p0171 dtc which i got from mazda cause one of my frenz work there and he hooked it up to an obdII scanner and showing that my car was running pig lean as -25 is the lowest it can run for lean, my car at idle was sitting on -25. he said my short term fuel system was fine but the long term is completely screwed. so i just ordered a fuel pressure regulator to have installed when it arrives. I was also wondering if anyone have any other ideas to get the a/f rate higher. already changed 1st o2sensor no help cleaned maf sensor no help couldn't find any air leaks, and the problem only occured when i put on the downpipe(s & j pipe)