Q: Car shaking after Coil and Spark plug change

Hi Kevin. OBD-II error codes don’t always tell the entire story or provide the exact reason for an engine misfire. In fact, most error codes have 5 to 10 possible sources, which can be misread or assumed is a specific component. For example, the P-0300 OBD-II code has 18 possible sources that can cause a random misfire. One of the best resources we have on our site are a series of OBD-II trouble code articles, like this one for example, where car owners with some technical knowledge and understanding on repair issues can read possible causes and repair solutions. You can review them by clicking on the advice tab and selecting the articles and questions section. Type in the error codes you are receiving and you’ll likely find some good tips. If you don’t have access to this information, have a professional mobile mechanic come to your location to complete a check engine light inspection.