The sensor seems to have only surface rust on it but no matter how much pressure I put on the wrench it just won't turn.I've sprayed liquid wrench but that doesn't help.
How to remove an oxygen sensor that just won't move. on 1990 Ford Ranger
Just start the engine prior to removal and let .it heat up. Worked for me, you just have to beware of the fact that this also heats up everything else. I've also found that if I put baking soda in boiling water and dip the ends of the sensors in it, sprinkling them with it also for a minute or two, would clearup problems that made your check engine light come on. I,ve cleared the codes on 3 cars, done this, and havin't had the codes or problems come back.
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Sometimes these things won't cooperate. The first thing I do is to take a torch and heat up the sensor red hot, and let it cool by itself. This will tend to shrink the O2 and it may work loose. Sometimes a 6 point socket with a long breaker bar on it will help get it moving. In extreme cases I have had to replace the exhaust part that the O2 was in because it refused to move.
how to replace a fan blade
Impact vibration on the wrench flats if reachable and nothing works better than PB Blaster for stuff like this.....