i have this sputtering problem .. it goes like this when i floor the the accelerator going all the way to 9500 rpm.. and when i release it staying on thje same gear my car does this sputtering missfiring like sounds.. how come? is this because im running on a stock air cleaner ? i have my fuel pressure set at 40 psi with the hose connected and a chipped mugen p30...help me guys...