Jeep liberty rough start ?

i have a 02 liberty my mom used it and put a lucas treatment in the gas 2days later the truck wont start and when it does it throws a greyish smoke idk what it could be i have to leave my foot on the pedal for it to start if i let go it turns off it threw ME CODES FOR COIL 1 2 3 AND I THINK AN INGECTOR TO A FRIEND TOLD ME IT WAS THE TPS OR SOMETHING LIKE THAT I DISCONECTED IT AND IT DOES THE SAME BUT Not that much smoke bt throws only one code p0123 any ideas sorry if i confused you all