G20 TCC code

[katsuragi06]

Hey guys I have a 1996 G20 that I have been trying to get past emissions. I need to get the check engine light off first and I'm getting three codes. First is for EGR and I believe I found the issue there and solved it but the code is still there. Second is knock sensor. Not sure if the sensor itself is bad but I bought a new NTK one to replace it. Haven't been able to get the old one off yet. Third is TCC solenoid valve I believe. I have no idea where to begin with this one or if it's the kind of thing I can do myself. Any advice would be appreciated. I've had this car for over six months and I'd love to get it all legal finally.