Your check engine light just turned on. Take a breath - 9 times out of 10 it's not catastrophic. Here's the exact 4-step process to figure out what's actually wrong, in order, before you spend any money.
The single most common check engine light cause. After fueling, if the cap isn't clicked tight or its rubber seal is cracked, the EVAP system detects a leak. Tighten it, drive 50 miles, and the light often resets itself.
Get a full diagnosis →Very common after 100,000 miles. The downstream O2 sensor sees inefficient catalyst output. Sometimes the sensor is bad ($80 fix), sometimes the cat is failing ($800-2,000). Code reading + sensor data tells you which.
Get a full diagnosis →Cracked intake hose or stuck purge valve lets unmetered air in. Engine runs lean, ECM throws a code. Often easy to find by ear - the engine hisses near the leak.
Get a full diagnosis →A single misfire code with the light steady usually means a worn spark plug or weak coil on a specific cylinder. If the light starts FLASHING, this is escalating - get to a shop today before the cat gets damaged.
Get a full diagnosis →Tell us your symptoms and any codes. In under 60 seconds you'll get a step-by-step diagnosis tailored to your car, the parts you need, and what a fair repair should cost.
Get My Repair Report →Cheaper than one wrong part. Backed by mechanic-trained AI.
If your scanner is showing one of these, that's your starting point. Tap any code for full causes and repair costs.
If the light is steady (not flashing) and the car runs normally, yes - for a few days while you diagnose. If the light is FLASHING, that means active misfire that can destroy your catalytic converter - drive only as needed and get it checked today.
Sometimes. If the issue resolves (e.g., you tightened a loose gas cap), the light typically resets itself after about 50-100 miles of normal driving. Persistent codes won't clear themselves until repaired.
No. Clearing codes erases evidence without fixing anything - and the light comes right back on once the fault is detected again. Read the code, fix the actual problem, and the light goes off on its own.
Because most code readings lead to parts purchases - and they want yours. It's a legit free service with no obligation. Just walk in, ask for a code read, write down the codes, and walk out.
Anywhere from $0 (loose gas cap) to $2,000+ (catalytic converter). The code tells you which end of that range you're at - which is why you don't want to guess.
One $5.99 report can save you from a $400 wrong-part install. Our AI walks you through the exact diagnosis, in plain English.
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