O2 sensor prob

See, my O2 is farther down the exhaust than that. Don't some of them have two O2 sensors?

Only one O2 sensor on Mazda trucks until 1994.The pic above is the stock location.If ur's is lower,u may have an aftermarket header with an O2 bung welded up.It is a one wire hookup as indicated above with the harness at the front of the engine under the intake.BJ