2007~2015 CX-9 Engine misfire or trans slipping or something else...

[Airshac]

I just bought an 2011 with 140k miles, I test drove a different one same age and miles and it did the same thing except worse...
Randomly the car shudders, at different speeds, different gears and different rpms. Sometimes the shudder is very slight and sometimes it is pretty strong.
Its not losing power or slowing down. Its not in the steering wheel like a front end component problem.
I can get it to go away by either giving it more gas or giving it less gas.
I have code for evap leak large so maybe it is connected to that.
Has anyone experienced this and know a solution?
Thanks!

 

[Odrapnew]

My wife's old 09 CX9 did something similar and it turned out to be a misfire.
It seemed to happen more at low rpm under load while the torque converter was locked (i.e. accelerating slightly on the freeway).
I could see the misfire counts go up on one of the cylinders when the shudder happened.
I replaced the plug (well, all 3 front ones) and the issue went away.

 

[Airshac]

My wife's old 09 CX9 did something similar and it turned out to be a misfire.
It seemed to happen more at low rpm under load while the torque converter was locked (i.e. accelerating slightly on the freeway).
I could see the misfire counts go up on one of the cylinders when the shudder happened.
I replaced the plug (well, all 3 front ones) and the issue went away.

That sounds very similar to what I have going on. Planning to do plugs and coils and see what happens.
Thanks!