You don’t want to sell every job. Trust me.

Vehicle diagnosis is no walk in the park. Proper diagnosis is critical and difficult, and it shouldn’t be done without doing the work.
Installing an old-fashioned filter on a modern vehicle because that’s what’s in stock may not be the best course of action.
Hordes of man-bunned millennials and newly-minted softroaders probably just picked up their pitchforks and are calling for my blood.