Engine Mechanical problem
1998 Lexus LX 470 V8 Four Wheel Drive Automatic 155k miles

I just completed a diagnostic test and the results were:
1- faulty fuse
2- loose wires
3- need new O2 SENSORS

first question- where is the fuse located
2nd- no idea how to check for loose
3rd- if the above 2 dont work how do i install the o2 sensors and where are they located?

thanks for your help,

doug morrison