Slow acceleration, rough idling, #2 cyl misfiring, Happened after using seafoam Options

[Cutrara]

I recently purchased a 96 st and thought I would run seafoam through it... took it up through the brake booster line. Of course it smoked like crazy, but was still smoking a few days later with a CEL on.

Took it to autozone, code P0302 #2 cylinder misfire. the plugs looked like they had a lot of grayish yellow deposits on them, #2 was significantly worse, so i replaced all the plugs with autolite double platinum and the car still has trouble accelerating... if i take off from a light it feels like i'm in third.

i also tried disconnecting the battery and resetting the afr (pull ecu hazard and efi fuses, idle for 10 mins) and still having problems. also checked all the plug wires, they look ok... I havent yet pulled off the dizzy cap.

Could it be the O2 sensor? but it didn't throw an O2 sensor code?? I suppose I could throw in the O2 sensors from my other celica, but my parts car is a 94 st obd-i and has a 1 wire front O2 sensor and my dd is a 96 st obd-ii cali-spec and has a 2 wire front O2 sensor. so idk if this will work. Haven't looked under the cars yet to take a look at the post cat sensors... if there are any?

I'm worried about my cat too cause of the misfiring. Any ideas?