I originally had what I thought smart brake and air intake issues.
The Mazda tech originally thought it was dislodged air intake module that led to overheating of sensors.
When I drove the car back home, the car kept on hesitating as I pressed on the accelerator. Then gray smoke came out the exhaust. I brought the car back to Mazda and had the tech drive along with me to see. When he tried to accelerate, the same thing happened (hesitation, smoke).
They did another diagnostic check and he said that the air/fuel mixture is off - too much fuel, not enough air.
They told me that I need to replace the fuel injectors.
I never heard of a 2 year old car needing new fuel injectors. Can a 2 year old car with about 6K miles need new fuel injectors?