I have a 2005 Supra Launch 21V with the upgraded 340 motor (ETX headers).

Every now and then the motor will set itself to run in protective mode, for things as simple as the battery being disconnected. My shop connects a diagnostic reader (like an OBDII reader) and determines if the code is just from the battery, for example, then "resets" it and re-tests.

I'd like to buy my own code reader so that I can save the 2-hour roundtrip to the shop, just to have them plug-in the reader and hit "reset".

Problem is, I am not sure if the 2005 Indmar 340 uses the MEFI-4 or MEFI-5. If it requires the MEFI-5, I'm probably out of luck because that appears to require a $600 box, but if it's MEFI-4, it seems I may be able to buy a $60 tool off eBay to diagnose and reset it.

Thank you in advance for any ideas!