PrencoPrenco is a leading manufacturer and supplier of OE quality ignition, electrical, brake, engine, and emission products to the automotive aftermarket. 1 Req Per Cylinder. When Replacing Ignition Coils it is Recommended to Closely Examine Wiring Harness for Cracked or Broken Wires or Loose Connector Contact Which May Cause a Poor Connection Resulting in Intermittent Misfires. - Failed or Burned Up VW/Audi Coils are Most Commonly Caused By Poor Electrical Connections, Wire Harness Breaks or Fouled Spark PlugsPrenco is a leading innovator and supplier to both Original Equipment Manufacturers and the aftermarket in the automotive, industrial and power sports industries