What should I check before flashing my WRX with ATLAS for the first time?

Build a short ritual and run it every time. It takes about two minutes and it prevents essentially every avoidable problem. **1. ATLAS version is current.** This is first for a reason. On versions 2024.4 and earlier, ECU recovery is not possible on 2023+ WRX manual ECUs, with 2025.1 and later resolving it upon first programming. If you have a 2023 or newer manual VB, updating is the difference between an interrupted flash being recoverable and being much worse. **2. Battery charger connected.** A high-amperage charger, not a trickle tender. During a flash the car sits ignition-on with the engine off, drawing current the alternator is not replacing. Failing that, confirm the battery can supply the electrical system for at least 30 minutes with headlights and auxiliaries off. If your car has ever cranked slowly on a cold morning, do not flash without a charger. **3. Factory file read and saved.** Your stock map, backed up somewhere off the laptop, named so it makes sense in two years. This is your return path before a dealer visit and your undo button. Do this before your first write, not after. **4. The map matches your hardware.** Read the notes item by item - intake and MAF housing diameter, fuel and octane, transmission, exhaust. Close does not count. If nothing matches your combination, you want a custom tune rather than the nearest option. **5. Electrical loads off.** Headlights, climate control, audio, anything charging from a USB port. Close the doors so interior lights are not running. Every one of those is current you are not spending. **6. Laptop will not interrupt itself.** Disable sleep and screen timeout, close anything that could pop up or steal focus, and have it plugged in or fully charged. This is the boring step that prevents the interesting problem. Two more worth adding for a first flash specifically. Do it somewhere unhurried - your garage or driveway, not a car park before you need to drive home. And datalog before you flash, because logging writes nothing and proves your adapter and connection are solid before anything is at stake. Then start it and leave it alone until it reports completion. Do not touch the adapter, the ignition or the laptop.