Are fuel system, fuel injector, EGR and engine cleaners safe for my vehicle? This is a question we get asked regularly and we feel the need to clarify. It's also a topic we discussed at length with the MD of a worldwide additives distributor. As such, we have quoted what they had to say on the matter. From our experience and testing you would have to seriously abuse a cleaner before it could cause any damage. Sure, there are many products that are useless and don’t deliver as promised but the main commercial ones we have tested are at least benign to an engine, including those..