KTuner.com

The tune description when opening a new tune tells you what it supports up to. Anything beyond that should be considered for custom tuning.

Oil grade is not something we can advise on and completely up to you.

When you flash an ECU you overwrite the data that's on it. It's not possible for an ECU to change tunes without flashing. Other saved items like fuel trims and adaptations are reset when battery is disconnected.

On our website we list all supported vehicles with ECU numbers and features outlined on each vehicle's application page. Check it out.

Contact support to have it repaired.

On the dealer page we list dealers with online stores at the bottom and most ship worldwide.

The unit can only be unlocked from an ECU with a matching VIN. We can't unlock it for you.

All of the supported ECUs can have VIN rewritten as well as immobilizer paired.

If you can't connect to the ECU you can't unlock it from it. Change the VIN for the new ECU to the VIN from the old ECU.

See the RSX/Swap page. You'll have to try the Base RSX AT codebase. Still no telling whether that transmission will be properly controlled with that ECU.