Way under powered

Recently I've removed the cat, changed plugs wires and coils (advance auto ones) I literally just did the wires today and that got rid of the misfires I was having randomly. Car will hold a solid idle now most of the time. Seems like when you turn the wheel or change ac it almost always messes with the idle. I tested the alternator a few days ago it was at 13.38 with just ac on went down to 13.03 with lights on. Battery is an optima red only a few months old. I've cleaned throttle body. Maf sensor. Filter (k&n) ess I just sprayed the dog **** out of it. Cleaned ssv. Sea foamed, water rotor wash. Still it just feels like it doesn't have the power anymore. Especially shifting from 1st to second it almost feels like it's not accelerating at al for a second. It does have a cel for rear 02 sensor which went bad with the cat. But to my knowledge that doesn't affect much? Unless it's actually just completely worn out? There's a slight hiss at idle very faint. Could that be a vacuum leak? I'm not experiencing misfires as of today with the new wires. The idle jumps around infrequently and it feels under powered all together. Sometimes more so then others. You can hear the relays and switches turn at idle and it will jump the idle around when it does that. I've reset the ecu done the 20 brake stomp. Which doesn't make my pressure gauge cycle but the cel does flash after i do that. Any thoughts? No starting issues hot or cold. Never have.