Fuel ratio gauge stays in full rich position.Please help

I did a t-5 to c-4 install, and now my air fuel gauge stays all the way in the full rich position. The motor used to run great. Now it runs like its loading up big time. I changed out one o2 sensor due to the ceramic getting cracked within the sensor. I also checked the whole o2 wiring harness for any damage and replaced the sparkplugs. Still runs like a** after all this. Now I'm thinking maybe due to disconnecting the speed sensor on the speed-o cable. Do you think that could be it? Any help would be great. All I did was the trans conversion. :confused: :bonk: