P0453 -What else can be causing high pressure in the fuel tank?

Question

This has been a nightmare. Codes since \'08: p0440, and currently p0453. I have replaced gas filler tube/ filler neck valve, purge valve, drain vent valve in the past 2 1/2 years. Code p0453 has been running for 2 years now; since the purge valve was replaced. The tech(s) I\\'ve had working on it have given up. The wiring checks out from ECM to FTP and back to ECM, no shorts. The FTP sensor is active. What else can be causing high pressure in the fuel tank?

Answer 1

Check the grounds/clean them.

the possible causes are:

•Open on FTP sensor signal wire

•Short to voltage on FTP sensor signal wire

•Bad FTP sensor

•Abnormally high pressure in fuel tank due to blockage in EVAP purge hoses or overfilled tank

•Loose/damaged FTP sensor connector

•Loss of ground to the sensor

Comments

What about bad charcoal vacuum canister??
Did you replace the fuel cap..