christoddrides

Alright so I am new here but I have been stumped so I need some advice. I have a 91 yota pickup with a 22re with 240k Original miles. Never had any major issues until the other day. I have a slight oil leak so I topped my oil off and threw in about half a quart of MMO which I had left. Then while I was driving it started spitting out some white smoke which I know can be normal with the MMO so I kept driving. Later on that day as I was driving, it started bogging down, sounding like it was knocking, spitting smoke on takeoff and backfired once. I am figuring the engine has taken a ˟˟˟˟ but I am not sure. Any direction on this would be helpful! Thanks