I turned off the internal pullup SCL and SDA (for I2C) of arduino
There is no need to do this. The internal pull up resistors are quite high and so they don't make much of an impact.
You only need one set of pull up resistors of 4K7 for all your devices.
Read again the information on the SparkFun level converter, people seem to wire this up wrong.
Is it a bi-directional level converter, some SparkFun converters are not. A link would be good.