run "i2cdetect -y 1" without sudo. It should take 1 second to show all addresses, if it takes 1 second per address means that your I2C driver is broken, I see this sometimes.
Go to /boot/config.txt, is this line there?
dtoverlay=i2c-gpio,i2c_gpio_sda=2,i2c_gpio_scl=3,bus=3
try removing it
Go to /boot/config.txt, is this line there?
dtoverlay=i2c-gpio,i2c_gpio_sda=2,i2c_gpio_scl=3,bus=3
try removing it