I realize this thread is older but I am posting this for anyone trying to locate this Fuel Tank Pressure Sensor because when I had to replace it on my car I could not locate it and was getting different info everywhere I looked. The FT Pressure Sensor is not in the gas tank. It is on TOP of the gas tank. You unplug it and replace it. You have to lower the gas tank on the 1999 Malibu to reach the sensor on top. This sounds difficult but it is not really. You DONOT have to unattach any other hoses or tubes. 1. Pull vehicle up on ramps. 2.You only have to place a jack under the tank to support it(easier done with less gas which makes it not as heavy.) 3. Unstrap the tank straps. 4. Lower jack just slightly enough for back of tank to come down a bit to reach your arm in there. 5. Use flash light to see and locate sensor which is more to the front of the tank. 6. Unplug the old sensor and plug in your new one. 7.reattach tank in reverse order. Done. It took maybe 40 minutes and that was to get all my tools out and everything. I used a 15mm socket with an extention to reach for removing the tank straps.

Can anyone tell me what this is and where i can get a replacment. Off a 2005 trailblaxer ls rear of fuel tank

It would help if you created a new thread, instead of posting this in a 3 year old thread.
Just what part are you asking about, the hose at the rear, or the white cap?