I bought a used 1997 explorer and it is very clean inside and out so I figured it was taken care of.the odometer says 154.000 miles but I found out the odometer is broke.when I go up hill it has no power and im hoping it doesn't need a rebuild.i brought it to advance auto and its coming up with lean on the o2 sensor but they never told me the code.im going to change the plugs and wires and maybe a fuel filter and see if it helps.any other suggestions would be helpful.its a 4.0 sohc

 

welcome to the sight. the code for that lean is 0174 and 0171. you can get some maf sensor cleaaner and clean up the maf or it could have a vac leak that's causing the code

 

thanks,i took out a plug today and it is definetly running lean.i cant find the o2 sensor any where on this engine.could some one tell me where it is?

 

it's usually under the car on the exhaust pipe gust in front of the cat. converter