Hi, I Have A 1999 Toyota Corola .

It Is An Automatic Transmission.. Odometer Not Working.. Even Though The Car Was Running Fine, I Did Some Changes Like The GearBox, Spark Plugs , fuel Injectors, fuel pump , Fuel Filter , Throttle Body..

I Have Noticed Quiet Recently That I Have Black Powder In The Exhaust When I Came Back From A Trip ..

I don’t Know If It Is The Lack Of Proper / Regular Maintenance  Attitude From Previous Owners..

I Do Regular Maintenance And Checks Whenever I Hear Any Funny Noise Ever Since I Became The New Owner …

Some Time Ago, I Noticed A White thin Smoke 💨 Come Out From The Engine Immediately  I Let Someone Start The Car… 

Another Time After An Oil Change , I Let Someone Drive The Car & I Noticed A Blue Smoke From The Pipe.. 

These Are NonSequential Situations 

I Asked A Mechanic About The Blue Smoke, He Said It Is Because Of The Fresh Oil Change ( I Don’t Know How True) 

Now I Want To Know What Caused The Black Powder In The Exhaust Pipe..

White Smoke & Blue Smoke 💨 What Could Be Wrong..? 

thanks