Stop driving soon
Something could damage the engine or leave you stranded. Find a safe place to stop.
- FlashingA flashing check engine light
- P0217The engine is running too hot
- P0524Oil pressure is too low
For the moment the light comes on
Your check engine light is on. Know what is wrong.
Plug in any $15 OBD2 adapter. In about a minute you get plain English, one clear urgency level, and a fair price range before you ever talk to a shop.
- Works with any ELM327 adapter
- Your answer before any sign up
- Cancel inside the app
Example scanP0455
Big leak in the fuel vapor system
OK to drive, fix when convenientCheck firstThe gas cap. Tighten it or replace it.
P0011Intake camshaft timing is too far ahead (bank 1)P0128Engine is not reaching normal temperature (thermostat)P0135Oxygen sensor heater circuit problem (bank 1, sensor 1)P0171Engine is running lean (bank 1)P0174Engine is running lean (bank 2)P0300Engine is misfiring in more than one cylinderP0302Engine is misfiring in cylinder 2P0340Camshaft position sensor circuit problem (bank 1)P0401EGR flow is too lowP0420Catalytic converter is not cleaning well enough (bank 1)P0442Fuel vapor system has a small leakP0455Fuel vapor system has a large leakP0456Fuel vapor system has a very small leakP0507Idle speed is higher than expectedP0524Engine oil pressure is too lowP0700Transmission computer has stored a code
How it works
Three steps. About a minute.
No car knowledge needed. If you can plug in a phone charger, you can do this.
- 1
Plug it in
Find the port under the steering wheel, near your left knee. Push the adapter in until it clicks.
- 2
Turn the key to ON
You do not need to start the engine. The adapter light comes on and the app finds it.
- 3
Tap Scan my car
The app talks to your car, reads the warning codes and checks the emissions monitors. Then it tells you what it all means.
See it work
The real app, start to finish.
This is a recording of the app itself, running a demo car. Tap a step to jump to it.
Recorded from the real Android app. Demo mode uses a pretend car, so you can try the whole flow before you buy an adapter.
One clear answer
Not a wall of codes. A decision.
Every scan ends with one of three levels, each with its own colour and icon. We never tell you the car is safe. We tell you exactly what to watch for.
Get it checked this week
Not an emergency yet, but it can get worse and cost more the longer you wait.
- P0302Cylinder 2 is misfiring
- P0087Fuel pressure is too low
- P0730Transmission gear ratio problem
OK to drive, fix when convenient
Get it looked at when it suits you, and keep an eye on the signs we list.
- P0455Big fuel vapor leak, often the gas cap
- P0420Catalytic converter is wearing out
- P0128Engine warms up too slowly
Urgency rules are code, not guesses. Misfires, overheating and low oil pressure always start at this week or higher.
P0302Get it checked this week
Cylinder 2 is misfiring
What it means
One cylinder is not burning fuel the way it should. The engine shakes a little and works harder.
Most likely causes, in order
- A worn spark plug
- A weak ignition coil
- A clogged fuel injector
Watch for
- The light starts flashing. Pull over and stop.
- Strong shaking or a loss of power
Pro adds a fair price range, how hard the fix is, and questions to ask your mechanic. Estimates only. A mechanic should confirm.
Try it now, free
Already have a code? Type it.
No adapter needed. We have plain English meanings for 159 common codes. Browse them all.
Made for real days
The light never comes on at a good time.
11:42 PMDriving home in the rain and the light comes on. Can you make it home tonight?
Quote Check, in Pro
Got a quote? Snap a photo.
Take a picture of the written estimate. In seconds you see every line, a fair verdict for each one, and whether the math adds up.
- Every line copied as written. Part numbers, hours, labor rate, fees and tax.
- It never makes up a number. If something is hard to read, it says unreadable.
- The math is checked. Line totals, tax and the grand total.
- Fair to the shop. No fraud talk. If the quote looks fair, we say so plainly.
Example estimate
Repair EstimateRO 10482
Front brake pads and rotorsParts 186.40, labor 1.5 h at 120.00366.40Fair
Brake fluid flushLabor 0.8 h, fluid129.99Ask about this
Engine air filterPart 64.0064.00High
Shop suppliesFee28.50Fair
Tax 8.25%48.58Total647.47
The lines plus tax add up to 637.47. This total is 10.00 higher. Ask the shop to check it.
Questions to ask the shop
- Does the maker's schedule call for a brake fluid flush at my mileage?
- Can you show me the old air filter?
- Could you look at the total again? I get 637.47.
Used-Car Check
Buying used? See what a cleared light can hide.
A seller can clear the codes so the light is off for your test drive. The car's computer still remembers. In a few minutes you get a red, yellow or green report you can share as a PDF.
Red if there is any stored, pending or permanent code, the light is on, codes were cleared less than 50 miles ago, 2 or more monitors are not ready, or the VIN in the car does not match the windshield.
Yellow if 1 monitor is not ready, or codes were cleared 50 to 300 miles ago.
Green for everything else, plus any open recalls from NHTSA.
$9.99 one time per car, or included with Pro. These rules are fixed code, not AI.
Used-Car CheckExample report
Red: get it inspected
Codes were cleared 23 miles ago and P0420 is still pending. Clearing codes can hide a problem until the light comes back.
- Pending codesP0420
- Codes last cleared23 mi ago
- Readiness monitors3 not ready
- VIN: car vs windshieldMatch
Car autopilot, in Pro
It keeps watch, so you do not have to.
Save your cars once. We check for new recalls every month and remind you about oil, tires and brakes based on your real mileage.
New recall for your SUVOpen safety recall from NHTSA. Recall repairs are free at a dealer.
nowOil change coming upAbout 300 miles to go, based on your odometer.
2dWhat is your mileage?Your car does not share it. Tap to update.
1wTrial ends in 2 daysYou will not be charged if you cancel before then.
3wRecall alertsChecked every month against NHTSA recall data for your year, make and model.
Mileage remindersFrom your odometer when the car shares it, or a quick monthly question when it does not.
Every car you ownKeep the whole family's cars in one Garage.
Honest pricing
One plain price. No tricks.
You see your answer first. You only pay if you want the full picture.
Scans
$0forever
Everything you need to know if it is serious.
- Unlimited scans
- Every code with a one-line meaning
- The urgency level for every scan
- One full Pro explanation, free
- Type a code with no adapter
The full picture
$39.99a year
7-day free trial, then $39.99 a year. Renews yearly until you cancel.
- Likely causes ranked for your exact car
- Fair price range, parts and labor
- Questions to ask your mechanic
- Clear Codes, with a clear warning first
- Quote Check, up to 10 a month
- Used-Car Checks included
- Recall alerts, reminders, every car you own
Used-Car Check
$9.99per car
For buyers who only need one report. No subscription.
- Stored, pending and permanent codes
- Readiness monitors
- Miles since codes were cleared
- VIN match check
- Open recalls and a shareable PDF
Price and renewal date firstShown before you pay, no scrolling.
Trial reminderWe remind you 2 days before a trial ends.
Cancel in 2 tapsGarage, then Manage or cancel.
No fake salesNo countdown timers, no fake discounts.
Coming soon to Google Play
Be ready before the light comes on.
Leave your email and we will send one message the day the app is ready. Nothing else.
We only use your email for the launch message. See our privacy page.
Questions
Straight answers.
Do I need a special scanner?
No. Any ELM327 compatible OBD2 adapter works, Bluetooth or Wi-Fi. Most cost about $15 to $25. Plug it into the port under your steering wheel and the app finds it.
Will it work on my car?
Cars and light trucks sold in the United States from model year 1996 on have an OBD2 port. If your car has one, the app can read its warning codes.
Do I have to pay to see what is wrong?
No. Every scan is free and shows the codes, what each one means in one line, and how urgent it is. You also get one full Pro explanation free. You see your answer before any sign up or paywall.
Will clearing the code fix my car?
No. Clearing the light does not fix the problem. It also resets the emissions monitors, so the car may fail an inspection until it has been driven for a few days. The app shows this warning before it clears anything.
Can I keep driving?
We never tell you a car is safe. Every result gets one of three levels: Stop driving soon, Get it checked this week, or OK to drive, fix when convenient. We also tell you exactly what to watch for. If your check engine light is flashing, the answer is always Stop driving soon.
How does Quote Check work?
Take a photo of the written estimate from a repair shop. The app copies each line as written, gives each line a verdict (fair, high, very high, possibly not needed, or unreadable), checks the math, and gives you 3 to 5 polite questions for the shop. It never makes up a number. Your photo is deleted after the check unless you save the report.
What does the Used-Car Check look at?
Stored, pending and permanent codes, whether the check engine light is on, the readiness monitors, how many miles and minutes since the codes were last cleared, and the VIN saved in the car compared with the VIN on the windshield. It adds open recalls from NHTSA and gives you a red, yellow or green report you can share as a PDF.
How much does it cost?
Scans are free. Pro is $6.99 a month or $39.99 a year, with a 7-day free trial on the yearly plan. A single Used-Car Check is $9.99 per car if you do not have Pro. Prices are shown with the renewal date before you pay.
How do I cancel?
Inside the app: Garage, then Subscription, then Manage or cancel. That opens your Google Play subscriptions. If you start a free trial, we send a reminder 2 days before it ends.
No adapter yet?
You can still type a code. Look up any common code on this website for free, or type the code plus your year, make and model in the app.