I am trying to build an op-amp circuit for a Hall effect sensor. The Hall effect sensor has an output range of 2.01V to 2.87V, and is fed to the Vin of the op-amp circuit below. The output V_out range is measured to be 3.71V to 0.81V. The 3.71V is largely off from calculations, which should be near 4.8V. The op-amp unit is a MCP602, which should give rail-to-rail output.
Using the same MCP602 op-amp as a comparator, I still get an output of only 3.71V. Swaping the op-amp for a LM358 unit, I still get a maximum output voltage of about 3.70V.
What could be the problem? Is it possible that all the op-amps I purchased are all faulty?