Engine codes

[raiders73]

121-Throttle position sensor and MAP sensor disagree with each other
122-Throttle position sensor voltage low

Ok I just changed out my tp sensor and the IAC Sensor last Saturday, the car ran great over the weekend, and stat all week long until Thursday, and the check engine light stayed on when I cranked it up. So I ran the codes and that is what I came up with. All of the senor are new. So how do I fix the problem and is it a big problem, all of the connections are tight nothing is loose.

Pac_Man