You wont be able to run more than 15 psi without a 3 bar map sensor, if its a stage 1, the 'greens' you have are probably light greens (355's). If you want to run more boost you will have to change your chip to a stage 2 one and get a 3 bar which at the moment can be quite hard unless you are prepared to shell out some redies. Also you will have to change your light greens for dark greens(803's). Hope this helps.