OBDII Scanner for my taurus...help..help!!!

I got my OBDII scanner bought from ebay today...Its a toptak 'TP-500 CAN OBDII' so I want to know if this is a good scanner or not? any bad reviews? thanks..

For the trouble code,, it definitlly read correctlly P0156, how ever the explanation is wrong. It says 'o2 sensor circuit' however, taurus's official maintenance guide says 'Downstream heated o2 sensor fault (bank 2)'.

I also got tons of live data from the scanner which I can not understand:
(I got those data when the vehicle is idle, shall I test the vehicle when it is running? )

*****************************************************
* PLEASE LET ME KNOW IF THESE NUMBERS ARE NORMAL? *
* *** what are the meanings of those codes *
* !!!!ALSO PLEASE GIVE THE NORMAL RANGE!!!! *
*****************************************************
Coolant Temp: 127 F

STFT - Bank 1: 0.7%

LTFT - Bank 1: -2.3%

STFT - Bank 2: 1.5%

LTFT - Bank 1: -1.5%

FUEL PRESSURE: 40.0 psig

Engine RPM 816 rpm

vEHICLE SPEED: 0 MPH

Ignition advance: 18 deg

Intake Air Temp: 71 F

MAF Air Flow Rate: 0.6 lb/min

Throttle position: 16.7%

Bank1 - Sensor 1: o2 output 0.225v

Bank1 - Sensor 1: STFT 0.0%

Bank1 - Sensor 2: o2 Output 0.090v

Bank1 - Sensor 2: STFT 99%

Bank2 - Sensor1: o2 output 0.225v

Bank2 - Sensor1: STFT 0.7%

Bank2 - Sensor2: o2 output 0.035v

Bank2 -Sensor2:STFT 99%

Well my downstream o2 senseor on bank 2 is dead why still has votage? strange!!!


Thanks for your view,, any kind of comment is highly appreciated!!!