I have had the same problems in Australia with my mazdacx7- has been sitting in my backyard for 4 yrs- to scared to drive the lemon 🍋 I was sold.
Has a serious manufacturing fault- Mazdaís staff members had and in house email to deny deny deny.
A pack of criminals.
Sludge build up- etc etc etc
Car blows smoke when u put ur foot down and looses all power.
How dangerous and they blame it on not enough oil changes- I am no mechanic but itís common sense that what they say is just a way to try and deny the real issue here.