waa driving and check engine light came on. Car started running rough. Idle it was missing. Once I got to highway speed and wasn’t hard on the gas it was smooth. If ya have it gas to go up an incline the check engine light would flash. Checked engine codes with the light and got 43. So I changed out the coil, plugs, wires, and new intake manifold gasket. Got it all back together. Reconnected neg battery cable and started it. Check engine light comes on right away. Still running rough. And now have code 31. Not sure if I screwed something up? Have something not connected? Very frustrated.