Steady or flashing?
A steady check engine light means the computer logged a fault. Get it checked soon, but you can usually keep driving. A flashing light means an active misfire is dumping raw fuel into the exhaust. Pull over, and call us. Driving on a flashing light can melt a catalytic converter in a few miles, and that is a $1,000+ part.
Try the gas cap first
A loose or cracked gas cap is the single most common cause of a check engine light. Tighten it until it clicks. If the light goes off after a few drive cycles, you're done.
Don't buy parts from the code
A code like P0420 says the catalytic converter efficiency is low. It does not say the converter is bad. The real cause is often an exhaust leak, a lazy oxygen sensor, or a misfire upstream. Replacing parts based on the code alone is how people spend $1,200 and still have the light on.
Get the free scan
We pull the codes for free, look at the live data, and tell you what actually failed. If you're heading to emissions, do this first: a lit check engine light is an automatic fail.
