1996 Toyota Tacoma Random Misfire

I have a 96 2.4l tacoma that has right under 200,000 miles on it. Most of the time it runs great but randomly it starts misfiring. Only when it’s up to operating temp but besides that there’s no rhyme or reason to it. When it starts missing the a/c doesn’t blow cold and my code reader won’t connect with the ecu. It’s been doing it a lot here lately. Any help is much appreciated.