The definition of a rule is  an official regulation, code of regulations or set practice. An example of a rule is that a red light means stop. An example of a rule is an employer demanding their employees arrive at 8am.
New injectors cost anywhere from $80-$120 apiece, making their replacement a somewhat pricey endeavor. There are three types of injector leaks-it can leak fuel into the manifold from the nozzle, it can leak fuel into the engine compartment from the fuel rail, and it can leak air (vacuum leak) from the manifold.
1 For instance, PepBoys.com offers three packages that range from $9 to $90. 2  According to this LATimes.com article, the average cost of a fuel injector cleaning will be around $69. There are many over-the-counter products that cost less than $10. 2  Simply pour the injector inside of the fuel tank, let your car engine run for 15 minutes and you are done. 3  Although this is a cost up front, it can help you save money in the future.