Incredible 2008 Volvo Xc70 Check Engine Light After Spark Plug Change Ideas. I checked the fuel cap and drove over the weekend, but the light remained on. Ignition system (failed coil packs) vacuum leaks;
If you have a flashing check engine light, turn off the engine immediately to prevent potential motor damage. However, the light may not be unrelated, which you must diagnose further to know. The light may also come on if the spark plug wires are defective or loose.
