Code p1456, gas cap tight

Question

Check engine light came on when I was away. When I got back car had been sitting undriven three days. Checked code, got P1456. Gas cap tight--when removed heard gas release, so was under pressure. Temperature in mid 70s. What other likely causes?

Answer 1

HI there,

This indicates a possible issue with the vent control valve or the purge solenoid. If these aren't working then there will be pressure built up inside the gas tank. If the pressure sensor doesn't read a change it is possible it would throw the code.