LIVE CODES
P0420 Catalyst Efficiency Bank 1· P0300 Random Misfire Detected· P0171 System Too Lean Bank 1· P0302 Cylinder 2 Misfire· P0455 Large EVAP Leak· P0430 Catalyst Efficiency Bank 2· P0442 Small EVAP Leak· P0101 MAF Sensor Range· P0440 EVAP System Malfunction· P0128 Coolant Below Threshold· P0507 Idle Control High RPM· P0301 Cylinder 1 Misfire· P0174 System Too Lean Bank 2· P0340 Camshaft Sensor Circuit A· P0303 Cylinder 3 Misfire· P0304 Cylinder 4 Misfire· P0335 Crankshaft Sensor A· P0401 EGR Flow Insufficient· P0113 IAT Sensor High Input· P0141 O2 Heater Circuit Bank 1 S2· P0011 Cam Timing Over-Advanced· P0446 EVAP Vent Control Circuit· P0496 EVAP High Purge Flow· P0016 Crank/Cam Correlation· P0606 ECM/PCM Processor Fault· P0420 Catalyst Efficiency Bank 1· P0300 Random Misfire Detected· P0171 System Too Lean Bank 1· P0302 Cylinder 2 Misfire· P0455 Large EVAP Leak· P0430 Catalyst Efficiency Bank 2· P0442 Small EVAP Leak· P0101 MAF Sensor Range· P0440 EVAP System Malfunction· P0128 Coolant Below Threshold· P0507 Idle Control High RPM· P0301 Cylinder 1 Misfire· P0174 System Too Lean Bank 2· P0340 Camshaft Sensor Circuit A· P0303 Cylinder 3 Misfire· P0304 Cylinder 4 Misfire· P0335 Crankshaft Sensor A· P0401 EGR Flow Insufficient· P0113 IAT Sensor High Input· P0141 O2 Heater Circuit Bank 1 S2· P0011 Cam Timing Over-Advanced· P0446 EVAP Vent Control Circuit· P0496 EVAP High Purge Flow· P0016 Crank/Cam Correlation· P0606 ECM/PCM Processor Fault·
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Know Exactly
What's Wrong With Your Car

AI car diagnosis in 30 seconds. First cause is free, no credit card. Full report $5.99 - less than a cup of coffee, a fraction of a shop diagnostic fee.

Not sure? See how it works  ·  Browse all guides  ·  🔧 Run a shop? AmpAuto Pro →
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DTCs in database
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Seconds avg diagnosis
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% accuracy on top cause
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Live Example
See a Real Diagnosis
2015 Ford F-150 5.0L V8 - rough idle, shaking at stoplights, no warning light yet.
ampauto.io - AI Diagnosis
2015 Ford F-150
5.0L V8  •  RO #47  •  Tom Bradley
✓ AI DIAGNOSIS READY
AI REASONING
PROBABLE CAUSES - RANKED BY LIKELIHOOD
CAUSE #1
Ignition Coil Failure
78% probability
Repair This Week
Coyote 5.0 has known coil-on-plug failures at 80-100k. Swap coil to adjacent cylinder - if misfire follows, coil confirmed.
CAUSE #2
Fouled Spark Plugs
55% probability
Repair This Week
OEM plugs at 94k are overdue. Carbon fouling on Coyote engines common with extended change intervals.
CAUSE #3
Fuel Injector Deposit
28% probability
Monitor
GDI deposits on intake valves restrict flow. Check fuel trims - if long-term exceeds +8%, injector cleaning warranted.
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The 50 codes behind 90% of check engine lights

Grab the free OBD2 cheat sheet: every common code with the likely cause and the DIY fix cost, so a $50 problem never turns into an $800 shop bill. Sent once, keep it forever.

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Why AmpAuto
Stop Guessing. Start Knowing.
First cause is free - no credit card required. Full report unlocks for $5.99. Shops charge $80-$150 just to read a code. We give you a complete AI diagnosis for less.
AI Diagnosis Engine
See exactly what the AI is thinking - TSBs it's drawing from, pattern failures it recognized, why it ranked each cause. Not a black box. Not generic Google results.
Exclusive
Ranked Causes by Probability
Every diagnosis ranks causes by likelihood with exact specs - fuel pressure values, resistance readings, PID parameters. Know what to check first, not just what a code means.
First Cause Free
Printable Mechanic Report
Full report unlocks for $5.99 - less than a shop charges to read a code. Includes all ranked causes, OEM steps, repair cost estimates, and a printable summary to hand your mechanic.
$5.99 One-Time
Process
From Check Engine Light to Answer in 4 Steps
Under 60 seconds from entering your code to knowing what's actually wrong - and what to do about it.
1
Enter Your Code
Paste your OBD2 DTC code and your vehicle year, make, and model. Takes 20 seconds.
2
AI Analyzes
AmpAuto AI cross-references NHTSA data, TSBs, and known failure patterns specific to your vehicle.
3
Get Your Free Cause
The most likely cause is free - no credit card. See exactly what it is and how serious it is.
4
Unlock Full Report - $5.99
Get all ranked causes, repair steps, cost estimates, and a printable report for your mechanic - for $5.99 one-time.
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No code? Use our symptom checker instead →
Comparison
AmpAuto vs The Competition
Most tools give you a code description. We give you a diagnosis.
Feature AmpAuto MECH AI SPARQ Carista VehicleScore
AI Diagnostic Reasoning (visible)
OEM-Specific Steps with Specs Partial
Live NHTSA Recall + Complaint Data Recalls only
Built-in Shop / Work Order Management
AI Customer Message Generator
Probability-Ranked Causes Partial
Works on Desktop (Shop Computer) iOS only
Free First Diagnosis
Pricing
Simple, Fair Pricing
Start free - no credit card. Shops charge $80-$150 just to read a code. We give you a full AI diagnosis for $5.99.
First cause always free - no credit card, no account required
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  • Most likely cause + explanation
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$29/mo
Unlimited diagnoses for mechanics and shops - with work order management.
  • Unlimited full reports
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  • Customer + vehicle database
  • Printable quotes
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Your First Diagnosis
Is on Us.

No credit card. No account. Enter your DTC code and vehicle, get a diagnosis in under a minute. Shops charge $80-$150 just to tell you what you can know right now for free.

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First cause free. Full report $5.99 one-time - no subscription.
📚 Popular Guides

The Most-Read Guides on AmpAuto

Real causes, real costs, and step-by-step fixes for the problems drivers Google most.

🔢 Top OBD2 Codes
P0420 - Catalytic Converter P0300 - Random Misfire P0171 - System Too Lean P0440 - EVAP Emission P0700 - Transmission Control
❓ Common Questions
Why is my car overheating? Why won't my car start? Why is my check engine light on? Why is my car shaking? Why is my car burning oil?
📊 Vehicle Problems
2017 Honda Accord problems 2018 Toyota RAV4 problems 2017 Ford Explorer problems 2015 Honda Civic problems 2019 Jeep Grand Cherokee problems
💰 Repair Costs
Catalytic converter cost Timing belt cost Radiator cost Rack and pinion cost Control arm cost
🔥 Trending Issues This Week Most-searched real-world fixes drivers are asking about right now
Hemi 5.7L MDS lifter tick Ford 10R80 shudder ZF 8HP transmission problems P0171 on Toyota RAV4 Emissions test cost by state AC blowing warm air Oil leak from engine Grinding noise when turning P0700 transmission control Sudden bad gas mileage
Browse all 647 guides →
Diagnose before you pay

Know exactly what's wrong
before you spend a dollar

AmpAuto was built by a software engineer who got quoted $1,800 for a $50 fix. The problem was never the repair. It was that car owners walk into the shop blind. Enter your OBD2 code or just describe the symptom, and the AI hands back the most likely causes ranked by probability for your exact year, make, and model, with real parts and labor costs. That is the same diagnostic leverage a good mechanic has, in about 30 seconds. Then you decide what to fix, what to DIY, and where you're being overcharged.

Free
First and most likely cause, ranked for your vehicle. No account, no payment.
$5.99
Full report: every ranked cause, OEM part numbers, DIY steps, and questions to ask the shop.
$0 scam
Paste any repair quote into the Quote Checker and see if it's fair before you pay.

Frequently asked questions

Everything drivers ask before their first diagnosis.

How does AmpAuto diagnose my car?
Enter your year, make, model, and either your OBD2 code or a plain-English description of the symptoms. AmpAuto's AI returns the most probable causes ranked by likelihood for your specific vehicle, with parts and labor cost ranges and what to check first. It takes about 30 seconds.
Is AmpAuto free?
The first, most likely cause and its cost range are free with no account and no payment. The full report, which includes every ranked cause, OEM part numbers, DIY steps, and questions to ask the shop, is a one-time $5.99. There is no subscription.
Do I need an OBD2 scanner to use AmpAuto?
No. If you have a code, enter it for a more precise result. If you do not, just describe what the car is doing (noise, smell, when it happens) and the AI symptom checker will diagnose it without a scanner.
How accurate is the AI diagnosis?
AmpAuto ranks causes by probability rather than guessing a single answer, and it is tuned to your specific year, make, and model instead of generic code definitions. It is a diagnostic starting point that tells you the likely causes and fair costs before you pay a shop, not a replacement for a hands-on inspection.
Can AmpAuto tell me if a mechanic is overcharging me?
Yes. Paste any repair quote into the free Quote Checker at /quote-checker and get a FAIR, HIGH, or VERY HIGH verdict with the fair price range and negotiation scripts. The Shop Overcharge Guide also lists the 12 most common ways shops overcharge and how to push back.
Run your free diagnosis →
Free first cause · No account · Read the blog · Free guides
📋

Free OBD2 code cheat sheet

The 50 most common check engine codes with the likely cause and DIY fix cost for each. Sent once, no spam.

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Built by Nate, a software engineer who got quoted $1,800 for a $50 fix.
About AmpAuto → · nate@ampauto.io