Root Cause Mechanic

Know what's actually wrong before you pay to fix it.

Root Cause Mechanic plugs into your car through many standard Bluetooth OBD-II adapters (ELM327) and turns what your engine is doing into an answer you can act on.

Most code readers hand you a number and a guess. This one runs an actual diagnostic process: it reads live engine data while you drive, asks what you're experiencing, and works out which explanations the evidence supports — and which it rules out.

What you get
• Plain-English fault codes — 663 DTC definitions, offline (P0300, P0420 and the rest)
• Live engine data captured over a real drive, not a single snapshot
• Ranked explanations with the reasoning shown
• A don't-buy list: parts the evidence says you do NOT need
• Check engine light diagnosis with recall lookups for your exact vehicle
• A maintenance schedule built from your VIN
• VIN scanning by camera

No proprietary hardware. Works with many standard Bluetooth OBD-II adapters (about $20). Nothing is locked to us, and we take no commission on parts or repairs.

Try it before you buy an adapter. The showroom vehicle replays a real, documented case end to end so you can see exactly how it reasons.

Root Cause Mechanic is a second opinion to help you ask better questions. It doesn't replace a qualified mechanic's inspection.