Hi everyone looking for help. I have a 2007 mazda cx7 and i just got it October 5 2021 it has begun to cut off while I'm driving or sometimes won't start. I've bought a new battery and a new alternator and a new starter solenoid. Today 1/17/2022 I just replaced all the fuses under the hood and the inside ones as well. I'm a female with pretty basic car skills but I'm not really understanding what else it could be. I'm also noticing smoke from the dual exhaust its whitish gray . it goes and comes anyone who can give me there opinion or advise would be much appreciated. Vin# JM3ER293670120133 if that. Helps , and buying a new car is not a option for me right now and being car less during the winter in kansas won't do either please let me know also I think I might have a bad negative ground as well it's on the screw on the fuse box.