amilinazzo

I have a 1993 ls400, thats been sitting for 2-3 months. When I started it recently it has been idling really funny. On start up the idle surges up to over 2k before dropping back down. it surges up and down maybe 5-6 times then it stays at 2500 and slowly raises twards 3k as the car warms up.
The power steering idle up has been deleted, I recently replaced both down stream 02 sensors.
the car idled perfectly fine up until now. does anyone know what my problem could be? ive checked for vacuum leaks, i believe my egr pipe might be cracked but its been like that since i bought the car. idk what could be causing this.