volvo

my friend put parts cleaner in his gas tank instead of injector cleaner and now his car isnt running very well. he ran the tank out and refilled it and nothing changed. i dont know what kind of volvo or motor it has

Start with a fuel filter (could be clogged with crud from the tank). Pull the plugs out and see if they're fouled. Depending on what the actual solvent and concentration was, the pump, lines, and injectors could be damaged.

Also could have damaged O2 sensors.

"your freind"
tell a little more- what was this Volvo doing that he put in something to make it run better
what exactly was put in and how much