I found i small math error in the formula!

On Line 103 in obdinfo.js
return (parseInt(byteA, 16) * 256.0) + (parseInt(byteB, 16) / 100);
A*256+(B/100)

This formular is slightly wrong

This is the fix!
return ((parseInt(byteA, 16) * 256.0) + parseInt(byteB, 16)) / 100;
((A*256)+B)/100

Thanks for fixing!
=)