01arroyo

I have an 01 automatic trans am. well the problem is that when i first bought the car i could burn it with me pushin on my brake. if i try to burn it now rpm's dont go further than 2,000. i dont have traction control. if i let go of the brake and floor it rpm's go up normal. the car runs fine. most people say i need a line lock but then how can u explain me burning it through second gear when i first bought it. my mods are fipk K&n intake and some long tubes with ory. no cats.