Recently, Check engine light came on. So I had the codes pulled and it was the EVAP, misfire in all cylinders and random misfire. (nothing changed as far as how the car feels)
Before I had time to really look into the problems, the CEL went away on its own. (yay!)

A few weeks later the light came back on and so I pulled the codes again. same codes.

Do you guys know if EVAP failure can cause misfire codes? Can these codes be related?



Thanks!

 

Just thinking out loud, try checking the valve on the back of the head, by the firewall, on top, and the hoses leading to/form it. If there is a leak, then there is going to be unaccounted-for air in the manifold, which could make the engine act a bit different, and be interpreted as knock.

Does the car idle fine? When engine is cold, hot? Top-end power is good? Or stumbles and hesitates?

Check all hoses, and I mean all, for bad fit, loose, cracks, etc.