I dont know how to add video on this post so I uploaded to YouTube. Like Title says my evo hasn't been able to go into gear when the car is on, but if the car is off and I start in in 1st or reverse car will engage and drive as well as letting me get into all the other gears once the car is moving. Recently when I've started it in 1st and drove it the other gears need a little more muscle on my side to get them into gear. I've replaced the slave cylinder fluid to see if that would fix it but its still the same. (Video I took) https://youtu.be/fUA8-gLXBAA

 

Sounds like clutch petal needs to be adjusted and or clutch is wore out and time to redo the clutch.