There are two basic types of injectors. Low impedance injectors with a resistance of around 2.5-3 ohms, and high impedance injectors of around 12 ohms. This can easily be measured by a multimeter across the two electrical terminals.

Early Hondas used low impedance injectors with a resistor pack. From about '92 to '96 Honda transitioned from low impedance to high impedance without a resistor pack.