I have this issue where i feel like im lacking power.
I drove around 20 miles with open headers, because my exhaust fell off and after i got the exhaust back the car felt like its lacking horsepower.
I replaced oil and oil filter, checked the spark plugs, and i cant seem to find anything wrong.
Engine is a stock LS1 with 1-3/4 long tube headers w/ 3" collector and a street tune.

Does anybody have any sugestions what to check or know what could be wong?