The former Corinthians frontman had been a huge success in Russian football and City paid around £19 million to bring him to Eastlands.
At the time that was a club record fee, since surpassed by the £32.5m City spent on Robinho.
However, Jo has only scored three times, and two of those came in the Uefa Cup against Omonia Nicosia.
Everton urgently need strengthening in attack, having recently had to rely on midfielder Tim Cahill playing out of position as a central striker due to an injury crisis.
Forwards Ayegbeni Yakubu and Louis Saha are among the players who manager David Moyes has been forced to cope without recently, and the proposed move could benefit both Everton and City if Jo sees regular action.
Jo's most recent appearance for City came in the FA Cup defeat to Nottingham Forest on Jan 3.