i have 03 se 6 speed. to make it short, i installed my franken intake back and forth with the stock(may be thats why?). my problem is, when i press on the gas the rpm shoots up and drops slightly and tries to catch it back to normal. for few days it was happening between 4th-6th gear. now its happening to 2nd-6th. another possibility might be an octane booster that i used once every week, i put octance booster for 3 weeks straight. 2 days ago my gas tank was half way empty so i filled it up, and my problem was solve for that day. during the rpm shoot i noticed lose of power, and my gas mileage is terrible. please help me out!

 

Put your stock air box back on and bring it to the dealer. It sounds like the MAF sensor is malfunctioning.