I have a controller that will not let me run in any CoD game regardless of settings. My other controllers does not have this problem. I don't know what's wrong with it. Is there a controller setting that I need to mess with to fix this issue? Thank for any advice.
The L3 button (as well as the R3) uses a tiny tact switch.
You may need to replace the actual button on the stick because (cheap) tact switches have shorter lifespan compared to rubber dome switch used in keyboards and pretty much every other button on the PS3 controller aside from the stick click.
This is because tact switches have a flexing rigid metal dome that crushes inward (thus the sharp click). Despite being designed to be pressed, everyone knows that a rubber band stretching will last longer than a metal paperclip being bent back and forth.