How do you change the o2 sensor on a 1999 Jeep Cherokee?

# The sensor is located in the exhaust manifold or exhaust pipe and is accessible from under the vehicle # Since the oxygen sensor may be difficult to remove with the engine cold begin by operating the engine until it has warmed to atleast 120 degrees # Disconnect the electrical wire from the oxygen sensor and carefully unscrew the oxygen sensor from the exhaust pipe.Be adviced that excessive force may damage the threads inspect the oxygen sensor for damage unless you are replacing it