Idle high then idle rough

I have the fuel injected crx si. I had an aftermarket intake when I bought the car so I put the OEM intake back on from the junkyard. After I did that the idle goes up to 2500rpms when cold and bounces from 1500 to 2000rpms. When it gets warm it goes to 700-750 rpms but bounces from 700-850ish and every once and a while drops to 500ish and feels like it wants to die and rattles everything. But never actually dies. It did the same with the other intake too except the high cold idle. I replaced the distributor because I thought that was it and nothing changed. It also has a new fuel filter but I installed it properly I believe.