Hello yall, about 3-4 weeks agoi had "electrical connector at valve body conductor plate leaking" issue on my 2003 c320.

I had this fixed, and ever since they fixed this, the car would (every now and then) go into limp mode (high revs, but barelly moving). Today i got the CEL on, and the codes are P0715 (input/turbine speed sensor circuit malfunction) and P0730 (incorect gear ratio). My question is what to do about these codes, i have done a lot of work on my audi, but never worked on a benz, is this a DIY type of thing? Also, do these codes have anything to do with the conductor plate leaking issue above ? I would greatlly appreciate any help. Thank you