This may sound stupid, but I have been trying to autotune my printer, but whenever I put in the numbers my software tells me to (Repetier host), into my firmware(Marlin firmware). It doesn't seem to have any effect whatsoever. My nozzle still does a sinusoidal temperature range of + or - 5 degrees from my desired temperature. I've attached a screenshot showing where I have been inputting my numbers, I may be putting something in wrong. Any advice would be greatly appreciated! Thanks a bunch

sincerely,
Max

Autotune is only a start. You'll need to fine tune it to your machine by hand. The more cycles you run in the autotune the closer you'll get to optimal numbers. If your EPROM is enabled you can make the changes by using GCode command so you don't have to recompile your firmware. When you get settings you like, then you can recompile your firmware.

PID tuning from Wiki
[reprap.org]