2001 Saturn SL1 code p0405 egr flow sensor a circuit low in

I currently have check engine light on..went to Advanced Auto Parts and the code p0405 egr flow sensor a circuit low input came up. The salesman suggested cleaning it first rather than selling me a new one. Once this was done my car now has a stalling sensation. If we remove the connection harness of the EGR valve when the car is running and then put it back on within 30 seconds it cures the problem of bucking and stalling. I just recently replaced the O2 sensor with a bosch product. The old sensor had failed too..but the new one does'nt look the same. Could the O2 sensor be causing the misfires?