Private users can do this but mower shops can't
Despite them not being manditory in OZ , if one is fitted & I bypass it then $ 5,000 for the first offence , $ 20,000 for the second .
It is called interfearing with a pollution control device .
I do have a box of bowl nuts ( never could understand why a bowl bolt is called a nut , but there is a lot I don't understand ) that I use for the purpose of diagnosing
engine problems & I have had a few instances or the wires coming loose or shorting causing random misfires .