so o2 senosr is coolant temp sensor or is it different one?? my rodeo having the same probalem from where i see you say, black smoke and blah. my shop say it need new coolant temp sensor. and from where you say about it have no socket, so you use 2mm open end wrench. mine did have the same thing and i use my 22mm open end wrench and man it WONT loose up. and correct me if i am wrong, 02 sensor is under the manifold right or on the head muffler????? help please. also one more thing before you fix them did your motor shake too???
-randall