2000 Toyota Tundra "2r 1" Questions

...1 is still the right side of the motor and sensor 2 would be the same as explained so you must change the back sensor it sounds like you have 4 O2 sensors 2 for each side of the motor 2R + 2L LATER ...

what is the firing order.Need to replace coil on plug number 7? looking into the engine compartment of any car the front of the engine to the left is always no 1 cylinder,so... 1l 2r 3l 4r 5l 6r 7l 8r