5speedstang

so as you know i have recently put lt headers on bbk. off road h pipe and flowmaster super 40's. i had the mil eliminators on it and had no problems. recnetly the service engine soon light came on and had it checked by a buddy who has a snap on and the codes are as follows po133 h02s11 ckt slow response and po153 h02s21 ckt slow responce. that means that the mils are not working. how can i shut off the rear 02s with out buying a tuner?