2003 Chevy Malibu No Power

Engine Performance problem
2003 Chevy Malibu 6 cyl Front Wheel Drive Automatic

I have a 2003 Chevrolet Malibu with 165000 KM on the engine Approx. September I got the Fuel Pump replaced. I picked the Car up 2 days later and the Check Engine light was on. I returned to the dealer 2 days later and they Ran the OBD 2 Code Reader on the car and never told me the codes. There were multipy codes showing up on the OBDII scanner. Now the car struggles to go up hills and Accelerating to highway Speeds. I can hear there is alot of Vacuum Back Preasure coming from the Air Filter side. It also has a rough idle in the morning when it first starts up.