Well,
I just picked up my car from the dealer and this is what was done:
The EGR valve was replaced and all the ports were cleaned.They also
performed the one time tune up.
The guy told me that there was excessive carbon buildup and suggested a
fuel injection service as well as throttle plate service which was not
covered under the extended emissions warranty.
I just drove the car for 5min from the dealer to my house but it seems
that it is a lot more responsive.
Thanks for your help halo2.