06 maxima transmission problem?

[Maxima95]

My 06 maxima when put into drive clunks ( as if a mount were broken, but they've all been replaced) also my SEL light is on and reads code P0731 gear 1 incorrect ratio. Now the funny thing is this problem will dissapear randomly. So when I put it into drive there's no clunk just smooth and the. The SEL light will dissapear. Then the problem comes back out of no where. Has anyone ever experience this before? Any Advice? I was thinking of flushing my transmission fluid. And of that doesn't work take it to Nissan for diagnostics.

[Rogue One]

Moved to correct forum.

[Maxima95]

Thanks