Check all the terminals for the injectors and also the ignitor, CAS and AFM for corrosion on the pins, ive seen them corrode and have intermitten contact issues many times, if they are corroded contact cleaner and/or some emery paper is the bext way to clean it.
The injectors are less likely to corrode, but the terminals in the plugs can stretch/wear out and cause issues, i had an intermittent miss with my supra that drove me mad for weeks and all i had to do was tighten the terminals back up on 1 injector plug.
also check out the coilpack plugs as well.