Guys,

I have a 1997 F-150 5.4 and I have replaced 3 of my 4 O2 sensors. The last O2 sensor that needs replacing is on the passenger side up infront of the cat, right past the exhaust manifold. I was able to get a wrench on it with a 3 foot cheater bar and still cant get it. Im afraid if I force it, I could do damage to the manifold or pipe. Anybody have any ideas as to what I should do? If I take it to an exhaust place they are going to want to drop the whole exhaust and that will cost some $$$. Thanks.

 

I forget what its called but theirs some type of bolt loosening thing like for torsion bar twists, maybe try something to loosen it

 

try to do it with the exhaust a little warm, might help losen the sensor. I know it works on on exhaust manifold bolts

 

Spray the heck out of it with some PB Blaster, and let it soak an hour or so. Then try to loosen it.