Check engine light on?
Find out what it really means.
Type your code below. We’ll tell you what it means in plain English, whether you can keep driving, what’s likely causing it, and what to check before you pay a mechanic. Free, for 5,000+ codes.
Plain English
No jargon, no manuals. Just what’s actually wrong with your car.
Can you keep driving?
The answer you actually want — and how urgent it is — first.
What to check first
The cheap fixes to rule out before the expensive ones.
Repair cost ranges
Know the ballpark price before the shop ever quotes you.
From warning light to answer in 3 steps
Read the code
Plug any OBD-II scanner into the port under your dashboard and read the code (like P0420).
Type it in
Enter the code at DecodeMyCar. No account, no app, no cost.
Know what to do
Get what it means, if it’s safe to drive, likely causes, and the first thing to check.
Common OBD-II codes
Start with the codes drivers look up most. Each one has a full breakdown.
“Can I keep driving — or will I make it worse?”
Most code lookups bury you in technical definitions. We lead with the one thing you actually need to know: a clear green / amber / red answer on whether it’s safe to drive, before anything else.
The 50 most common OBD-II codes
A printable cheat sheet: what each code means, whether you can keep driving, and the cheapest thing to check before the mechanic. Free to your inbox.