ugh!!! okay i replaced one sensor that came out easily but was a monster pain in the ass to reconnect. i will upload a picture later but the 02 sensor was covered in black. looked online and it looks similar to being an oil fouled sensor. i went to replace the 2nd on and while it was placed much easier the sensor is frozen and stripped in there. ived tried it all, lubes, wrenches, hammers and locking pliers. wont budge i need to replace it. ive seen videos of ppl heating up the bolts to loosen them. would anyone reccomend this? other than the code for this messed up sensor the truck is riding smooth. its coming down to heating it up and taking it out or taking it to a place to have them remove it. i struggled with it for 2 hours yesterday.