GETTING MY TOYOTA 4AGE FOR SALE TO WORK

What other sensors ought to I look to include around the regular 4age, inlet air temp and a wideband sensor are already proposed, is there anything else I should really insert? When there is not a patch harness, how hard is it to help make my own patch harness supplied I have no former wiring expertise? Cheers PaulShould you have swapped out the OE