I can't erase CEL codes and other input needed

[chubbylove]

I need some help...
I can't erase my Check engine light codes. I have tried the two wires in the black diagnostic terminal and turning the car on and off which didn't work, and I have tried disconnecting the battery for 45 min and turning the lights on while it's disconnected to get rid of the residual voltage. The codes are still there. Its a MAF sensor code (Which I replaced that sensor) both O2 sensor codes, a vehicle speed sensor code, a knock sensor code, and the EGR code. I want to erase the codes because I don't think all those sensors are failing.
It runs great for about 15 to 20 minutes of driving then the CEL comes on and it shifts in incorrect spots, it has poor throttle response, and loss of power (This all only happens when th check engine light is on). If I punch the gas the CEL light will go off momentarily but will come back on within seconds or the next time I return to idle.
Any information helps.
Thanks for taking your time to read this and for your input. Also it's a 94 front wheel drive if you're interested.