hey im having the same problems with my gsrturbo. it kind of stutters at around 4500-5000 . and i as well have a very deep smell.... gets me kinnna light headed haha.... but im sure wen i get it tuned it should be running better... im still running the piggy back ( blue box ) not sure what to go with.. i was thinking hondata.. but thats alot.. does anyone know how much they run for... or any other good ecu's ... and give me the prices if possible