If it is the same as the 2000, then it's in the fuel tank. The directions for removal from the FSM are:
1. remove the fuel tank.
Caution: the fuel tank pressure sensor must be disengaged from the fuel tank before it can be removed. Failure to do so can cause damage to the fuel tank pressure sensor or the fuel tank.
2. Remve the fuel tank pressure (FTP) sensor.
3. Disconnect the electrical connector.
4. Press down and rotate the FTP sensor counter-clockwise and remove it from the fuel tank.
5. install in reverse order of removal.
6. Perform Leak Test.
7. Perform Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle Test.
Looking at the troubleshooting section, it could be associated with a P0452 (input below maximum) or a P0453 (input above maximum) code. (Again, all this is from the 2000 Factory Service Manual. I have no idea if it is the same for your 96!)
Possible causes for the 0452 include:
-Contamination. Sensor is completely submerged in fuel. Fix is to drain tank and refill to proper level.
- low voltage. Requires a scan tool. Voltage less than 0.22v on the tool. If so then a jumper must be installed between the vref and ftp at the connector. If voltage is then 4.0 to 6.0 v, the sensor is faulty. If not, then measure the voltage with a tester at the connector. If the measured voltage is 4.0 to 6.0 v then the PCM is faulty, fi not then there's a short in the wiring somewhere.
for 0453, possible causes are open FTP wire, short to vref or power, damaged FTP sensor or PCM. Again, a scan tool is required for some of these tests. First test the PCM with the scan tool. Then check that the FTP voltage is greater than 4.5v. Disconnect the connector and measure the FTP voltage. If it is above 10.5 volts then there is a short to power. To find that you need to disconnect the PCM and install a breakout box to measure the voltages between PCM test pin 62 (ftp) and PCM test pin 103 (PWR GND) if the voltage is less than 10.5v, then the PCM is faulty. If higher, then the short is somewhere in the wiring harness.
If the FTP voltage was below 10.5 volts then attach a jumper wire between the SIG RTN and FTP at the FTP connector if the FTP voltage is below 0.10v then measure the voltage between VREF and SIG RTN to make sure it is between 4.0 and 6.0v. If it is, disconnect the PCM, install a breakout box and measure the resistance between PCM test pin 62 (FTP) and PCM test pin 90 (VREF). If the resistance is greater than 10 ohms, then replace the FTP sensor. If not, then there is a short in the wiring harness between FTP SIG and VREF.
If the FTP voltage was above 0.10v, then disconnect the PCM and install a breakout box. Measure the resistance of FTP circuit between PCM test pin 62 and the FTP sensor harness connector. If the resistance is more than 5.0 ohms, then there is damage to the wire in the FTP harness somewhere. If less than 5 ohms, then measure the resistance of the SIG RTN between PCM test pin 91 and the FTP connector. If resistance is too high then the problem is damage to that wire. If resistance is less than 5 ohms then measure the resistance between PCM test pin 62 (FTP) and PCM test pin 90 (VREF). If the resistance is greater than 10K ohms then replace the PCM. If lower than 10K ohms, then there is a short in the harness between FTP and VREF.
FTP wire is Red/Pink
SIG RTN wire is Grey/Red
VREF wire is Br/White.