Hey guys new here. So I bought a 2000 ford Mustang 3.8 v6. Has about 170k. Some issues which are driving me nuts is my rpms when I'm driving around 60 mph are between 2500 and 3000 rpms. It seems like my overdrive isn't working. I hit the button, the light comes on, but no downshifting. Also, all four of my o2 sensors are out. I need some help/ advice please and thank you in advance.

 

Your car will not shift into over drive until it goes into closed loop. And it will not go into closed loop untill the 02 sensor issues are adressed.

Post the codes your getting , since there are several different codes for 02 sensors it will be easier for someone to help if we know the exact codes your getting.