01 — Symptom-first
Start from what you noticed
A noise, a smell, a warning light. We rank the likely causes by how common and how serious each one is, then send you to the fix that matches.
Browse symptoms →howtofixcar.com
DIY car repair guides, indexed by symptom, code, and vehicle.
We pull torque specs, part numbers, failure modes, and typical mileage ranges from public technical sources, then assemble them into one guide per repair. The method is documented on the site, and the guides are organized around the way people actually search.
Three ways in
Browse by approach
Every guide is cross-linked across symptom, code, and vehicle, so you can start from whichever one you already know.
02 — Code-first
Look up an OBD-II code
Your scanner returned a code. We explain what it means in general, what it usually points to on your specific vehicle, and which checks to run first.
Browse OBD codes →03 — Vehicle-first
Browse by your car
Year, make, model. We pull together the problems that recur on a given generation and the codes that come with them, then point you at the repair guides written for that exact platform. Engine-code differences are called out where they matter.
- 2015 Honda Civic
- 2018 Ford F-150
- 2018 Toyota Camry
Published guides
Start with these
We publish in small batches and check each guide before it goes live. These are the ones up now.
Symptom
Car Won't Start: How to Diagnose No-Start vs No-Crank in 5 Minutes
Car won't start? The first question is 'no crank' (dead silence or click) vs 'cranks but won't fire'. Each has a different fix tree. Here's the 5-minute triage.
Updated
OBD-II code
P0420 Code: Catalyst System Efficiency Below Threshold — Causes, Diagnosis, and Fixes
P0420 means the catalytic converter is not cleaning exhaust gases efficiently. Causes range from a $100 O2 sensor to a $2,000 catalyst replacement — here's how to tell which fix you need.
Updated
How-to guide
How to Jump Start a Car Safely: Step-by-Step With Cables or a Pack
Jump starting wrong damages electronics or starts fires. Here's the correct cable order, the right places to clamp, and what to do with modern start-stop vehicles.
Updated
Symptom
Check Engine Light On: What It Really Means and What to Do Next
The check engine light tells you a fault code is stored, not which one. Solid light is usually drivable; flashing light means stop now. Read the code at any auto parts store for free, then triage from there.
Updated
Symptom
Engine Overheating: What to Do Right Now and How to Diagnose
If your temperature gauge is climbing, stop driving within the next few miles. Continued operation cracks heads and warps blocks. Here's what to check after you've safely pulled over.
Updated
Symptom
Car AC Not Blowing Cold: How to Diagnose Before Spending Money
AC not cold? About 80% of the time it's low refrigerant, but the leak source matters more than the recharge. Here's the order before you hit Pep Boys for a $30 can.
Updated
Symptom
White Smoke From Exhaust: Steam, Coolant, or Head Gasket?
White smoke from the exhaust is normal at cold start (steam) and a warning at any other time (coolant in the combustion chamber). Here's how to tell the difference.
Updated
Symptom
Oil Leak Under Car: How to Find the Source by Color and Location
Oil leak under your car? The color tells you the fluid (engine, trans, brake, coolant) and the puddle location tells you the source. Here's the field-ID guide.
Updated
Why this exists
How we build this content
Most DIY repair information is scattered across forums, paywalled manuals, and half-finished videos. We gather the underlying data and turn it into one clean guide per repair, organized the way you'd actually look for it.
- Data, then prose
- Every guide starts from a structured data package: torque values, OE part numbers, and documented failure modes, all collected from public technical sources. We do not invent specs.
- AI-assisted, transparently
- We assemble the writing with AI using standard subscription tooling. Every page carries an AI-assisted notice, and the model we used is recorded in the article's metadata.
- Safety-flagged
- Any procedure that involves brakes, airbags, fuel, or high-voltage components carries an explicit warning at the top of the page, and we keep that language blunt rather than reassuring.
- Corrections first
- Fixing a known error takes priority over publishing something new. Each guide keeps a changelog, and the methodology page lays out how the whole process works.
FAQ
Common questions
- What is howtofixcar.com?
- A reference library of DIY car repair guides, organized by symptom, OBD-II diagnostic code, and vehicle (year + make + model). Every guide is built from a structured technical data package and assembled with AI assistance.
- How are the guides written?
- We collect data points (torque specs, OE part numbers, common failure modes, mileage windows) from public technical references, including the NHTSA vPIC and complaint APIs, manufacturer service bulletins, and documented owner-reported failure patterns. That data feeds prompt templates that draft each section of the guide, and the output runs through automated quality checks before anything goes live.
- Can I trust an AI-assisted repair guide?
- We do not ask you to trust the writing. We ask you to verify the data. Every torque value, part number, and procedure step traces back to a structured input you can check, and the full quality process is on our methodology page. Any procedure involving brakes, airbags, fuel, or high-voltage components carries an explicit safety warning at the top, and we recommend a certified technician whenever you are not confident.
- How do you choose what to publish?
- We look at what symptoms people search for, which OBD codes scanners actually return, and which problems are common on specific vehicle generations. We only publish where we have enough structured data to build one coherent reference, so there is no guide without a data package behind it.
- Is this free?
- Yes. The site is editorial — we do not charge for access. Over time we will introduce affiliate links for replacement parts where they help readers (Amazon Associates). Those links will be disclosed; they will not influence the order or recommendations in a guide.
- How do I report an error in a guide?
- Use the contact page. Include the URL of the guide, the specific value or step you believe is wrong, and a source if you have one. Editorial corrections take priority over new content; each guide carries a changelog showing what was changed and when.