Hey guys, I am having a problem with the O2 sensors on my 95 Ranger with a OHV 4.0 with a manual transmission. The CEL has been coming on and i keep getting the codes P1443, P0135, and P0155. The codes are O2 sensor malfunction bank 1, 2 and manufacturer emission control malfunction. I have replaced both O2 sensors cleared the codes and the CEL keeps coming on. I have checked both harnesses and plugs for damage and everything looks fine. I am about to pull my hair out! Any help or suggestions would be much appreciated.

 

There looks to be 15A fuse for the heated 02 sensors located at slot #20 inside the engine compartment fuse box. Check your owner's manual for the exact location, then check the fuse.

Regarding the 1443 code: https://www.ford-trucks.com/forums/1...rol-valve.html

 

I checked the fuse in fuse box inside the truck and it was good. Is there another one in the engine compartment as well? Thanks for the help. I really appreciate it.

 

I just found the blown fuse in the engine compartment fuse box and replaced it. Guess what, no more Check engine light! If I lived in Connecticut i would buy you a 12 pack! Thank You! I have been beating my head against the wall with this for a couple of weeks. I would have never guessed that there were two fuses for the same circuit.