Is my KA toast???

[Klimaxx805]

Hey guys, I’m new to the 240 scene a few weeks ago I bought a 91 240 SE coupe and love it. The car ran fine since the day I bought it but then I took it to get it smogged and it failed NOX (3824ppm @ 15 mph and 3309 @ 25 mph). The guy blamed the EGR. I checked the EGR for vacuum leaks and pulled up on the bottom of it and the car stalled so I know it’s working. So I came on the forum and did a search, I came across a few threads on seafoam. I also read about over inflating the rear tires, driving the car hard before the re-test, etc…so I bought some seafoam. I disconnected the brake booster vacuum line and slowly poured about half the bottle into the motor. My friend started revving up the engine and we smoked out the neighborhood. I din't pour any into the gas tank because I still had like half a tank. I drove the car to the gym and back with a big smile on my face because the car seemed to run smoother. The next morning as I was going to work when I went to shift into second the car bogged down bad around 4000 rpm. I kept giving it gas but the car wouldn’t accelerate, so I had to drive in the bike lane and let traffic pass…saw my friend drive right past me in his S14 and the mother fu*#er didn’t pull over to see what was wrong (HAHAHA sup Robbie, Dub City!). So I nursed the car home jumped in my other car and went to work. I searched the forum again and read about changing out a bunch of stuff after running seafoam. So I changed my sparkplugs, fuel filter, O2 sensor, cleaned the following with carb cleaner, MAF, IACV, EGR, and throttle body. I checked to make sure the fuel injectors are all working and the car is getting worse. Now it wont rev past 2500 rpm, it just boggs really bad and wont rev up. So I searched yet again and was convinced I had a bad cat. I pulled the cat off yesterday and the car still runs like shit. I’m ready to drive it off a cliff but the sad part isn’t drive able to the nearest one. I don’t know what else to do, it idles fine and no check engine light. Please help any suggestions would be greatly appreciated. I plan on going SR later this year and would like to keep the KA for the time being. Please help me and my gross polluter.