Reasons For Spark Plug Resistors

Many people have this misconception about spark plug resistors. Some think that the resistor will stop oil fouling or may stop the deposits from entering or exiting the spark plug chamber. Instead, the resistors were created for EMI (electromagnetic interference) or RFI (radio frequency interference). With the spark plug and spark plug wires, this is extremely minute amounts of radiation that are emitted by electric circuits which carry rapidly changing signals. These unwanted signals interfere with other signals sent from other electric or electronic signals. When a spark moves or jumps the gap on the spark plug, it creates electromagnetic field causing a number of problems, such as poor spark plug performance. But the EMI or the RFI can also cause more severe problems with your vehicles computer or radio, or other vehicle electronic or electrical systems. Though the spark plug and spark plug wire manufacturers have been coming up with new technologies to retard the effects of EMI or RFI, the people who design the cars, trucks, SUVs and vans we drive everyday are working hard to help with the effects of EMI or RFI.