Steady vs. flashing, the gas-cap myth that's actually true, and why a $20 code reader can't tell you what's really wrong.
Few dashboard lights cause as much anxiety as the check engine light. The good news: it's often something minor. The important news: a few situations mean you should act now. Here's how to tell the difference.
A steady light means the car detected an issue you should get checked soon, but you can usually keep driving carefully. A flashing light is serious, it signals an active misfire that can dump raw fuel into and destroy your catalytic converter. If it's flashing, ease off the throttle and get to a shop; don't keep driving hard.
One of the most common (and cheapest) triggers really is a loose, damaged, or missing gas cap, it creates an evaporative-system leak the car detects. Tighten it; if the light doesn't clear after a few drives, it's something else.
A parts-store scanner reads a trouble code like "P0420," but that code points to a symptom, not a definitive part. P0420 might be a catalytic converter, or an upstream oxygen sensor, or an exhaust leak. Replacing the converter on a guess is how people waste hundreds of dollars. Proper diagnosis tests to find the actual cause.
And remember: a lit check engine light is an automatic emissions failure, so it's worth sorting before renewal time. TAB Motors diagnoses it right the first time, call (703) 243-3080.
Virginia inspection, oil, brakes, tires and more on Old Dominion Dr. Free air, free coffee, and a straight answer every time.