I doubt you caused this by disconnecting those sensors. I have done the separator twice, ICV once, and some other things, and had all those connections you mention off upwards of a dozen times. It sounds like your ECU needs to be reset.

If the car hasn't even started since you did the separator, it cannot have run long enough to get a pending code from one of them, and then get it again and turn it into a full blown fault code and flash the SES light.

I think this is something else.

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2001 E53 3.0 5pd