Posted on 9/26/2025
That small orange or yellow icon on your dashboard can appear without warning. Sometimes your car still seems to run fine, and other times there’s a noticeable change in performance. Either way, the check engine light is your car’s way of saying something isn’t right. It could be a minor issue, or it might point to a developing problem that could lead to expensive repairs if left alone. Here are some of the most common reasons this light turns on, and why it’s important to have it diagnosed promptly. 1. Loose or Faulty Gas Cap This might sound too simple, but it’s true, a loose gas cap is one of the most frequent triggers for the check engine light. If the cap isn’t sealed properly, it can cause a drop in pressure within the fuel system. That disrupts the evaporative emissions system and triggers a fault code. Before assuming the worst, always check to make sure your gas cap is tight. If the light doesn’t go off after a few ... read more