Sorry, what does VIN specific ECU mean? Means ECUs can only be used on one car it is paired with and can't be changed? But I can interchange 2 ECUs paired with the same car right?

 

Vin specific means that there is an immobiliser code for every individual P car. This immobiliser code is stored on your ecu. When you flash the car, the tuned file also must contain this immobiliser code for the car to run, thus the tuned file is also specific to that particular car.
You can have any number of ECUs mated to the car, no problem. But the software or tune on those ECUs are specific to your individual car and will not work on another unless the immobiliser code in the tune is changed for the new car. Not many tuners like to do that.

 

Got it. Thanks! I guess it seems I just bought myself an extra ECU with no additional benefit.

 

Will the new ECU trigger CELs? I'm still thinking if I should cut my losses. Forget about the paid for flashed new ECU and just flash the stock ECU.

 

No reason why CELs should be triggered.
You're fine.

 

That's good to hear. At least not all's lost. Phew!