hi guys,
thanks for the inputs...

i'll try turning out the LSN and try again.
as what brian said. i'm not having my car die-off after 5s after lifting the nose up. my car die-off immediately when the nose is lifted.

also what i notice is that after the straights at full throttle and off throttle going onto a corner, my car would high idle for about 3-5s before dropping to normal idle.