Know exactly what's wrong with your car before you spend a dime at the shop — or fix it yourself with confidence.
You know something's off. Check engine light is on. But a diagnostic fee just to read a code? That's money you could spend on the actual fix.
P0171. Great. You Googled it — 50 forum posts, 50 different answers. Replace the O2 sensor? MAF sensor? Intake gasket? You're guessing.
You've got tools. You've watched the YouTube videos. You just need someone to tell you the actual problem so you can fix it right the first time.
You don't need an OBD scanner, a code reader, or any hardware at all. Just open Wrench on your phone, describe what's going on with your car, and the AI walks you through a real diagnosis — step by step, question by question — like having a master mechanic on the phone.
Describe your symptoms — a noise, a vibration, a warning light, a smell — and Wrench asks smart follow-up questions to narrow it down. It's a real back-and-forth conversation, not a generic Google result.
Wrench doesn't give you one answer and stop. It digs in. When did it start? Does it happen cold or warm? At what speed? Every question narrows the possibilities until it finds the real problem.
That noise just started on your way to work. Do you keep driving or pull over? Wrench tells you immediately — no Googling, no guessing, no panic.
Walk into a shop knowing exactly what's wrong. No more "well the tech says you need..." surprises. You'll know if they're telling the truth — and what a fair price looks like.
No hardware to buy. No software to install. No accounts to create. Open the website on your phone, type or speak your problem, and get answers in seconds.
If you want live data from your car's computer — real-time sensor readings, full module scans, code clearing — grab a $15-50 Bluetooth OBD adapter. It's optional, but it unlocks the full pro experience.
This is what it actually looks like. Just you and the AI, working through the problem together.
Love working on your own car? Grab a Bluetooth OBD-II adapter ($15-50 on Amazon) and Wrench becomes a full diagnostic scanner — with AI that analyzes your live data in real-time.
Scan all 8 modules — engine, transmission, ABS, airbags, body control, and more. Read every stored and pending code, not just engine codes.
Watch your engine's sensors in real-time — RPM, fuel trims, O2 sensors, coolant temp, knock, timing. The AI watches WITH you and spots problems as they happen.
Fixed the problem yourself? Clear the check engine light right from your phone. No trip to AutoZone needed.
The conversation-based diagnosis is great. But when the AI can see your actual sensor data, it goes from "probably this" to "definitely this — here's the proof."
See the difference? Without the adapter, Wrench gives you a great diagnosis based on your description. With the adapter, it shows you the actual proof from your car's sensors. Both work. The adapter just takes it to another level.
Start diagnosing for free. No credit card. No mechanic degree required.
Start Diagnosing — Free During Beta