The power of any given coil is only as good as the coil\'s ability to transmit its power to the plug. Our spark boot inserts replace the low quality OEM springs with a precision copper-beryllium winding. Our springs have 80% less resistance, and are constructed from rare earth metals that will not corrode or deteriorate. The kit also includes isolation sleeves to prevent your newfound spark energy from jumping through the isolator. This kit will work on all 2.4 and 2.3 engine combinations.