VersaTune User Forum

I have the full versatuner for a 2011 Speed3. Ive successfully flashed a couple of the base tunes to the car. The turbo recently grenaded it's oil seals and wrecked the cat at the same time. After the car was put back togeather everything runs fine but we are getting a MIL light for no voltage from the rear O2 sensor. Tried a couple of different sensors (new) and checked all the wiring. All tested good. So, we suspect an issue with the ECU.

Does versatuner provide for mating a replacement ECU with a car? Used or new?

Any advice from those who know or maybe have experienced this before?

You will have to contact tech support at versatuner and let them know about the situation, provide proof of the old ecu being taken out of the car, and so on. Because it's a vin based license and because ecus go bad sometimes such situations have been considered.

VersaTune does not facilitate ECU swaps on Mazdaspeed3. You would have to take it to the dealer to get a new or used ECU initialized and immobilizer/keys programmed. The dealer will be hesitant to program a used ECU, although it can be done.
Check continuity from the ECU pins to the O2 sensor plug. The problem may be in the harness. ECUs rarely go bad.