I drive a 2012 Acura MDX with 125k miles and recently the car was mis firing. I have my own obdii scanner and the codes that came up were for a cylinder mis fire. I go to Acura and they first said they have to change all 6 coils and the spark plugs. Then they said it isn’t the coils it’s the ECU that needs to be changed. I get the spark plugs and the ECU changed. My question is they said they reprogrammed on of the keys but I had a second pair of keys that I brought in a day after to get programmed. But first I checked if the second key would still work without to being programmed to the new ECU. Surprisingly enough the second key worked. Did they actually replace the ECU or were they lying? Did they only replace the spark plugs which solved the problem and charged me for the spark plugs and ECU? Or do the keys not need to be programmed to new the ECU to work?