p0440

This code just came up for me 2 days ago. I had been having the p0441 code for a little while after I got the vehicle, but it cleared itself and hasn't been back for several months. When the check engine light came back on I thought it was going to be the 0441 coming back, but it was a p0440 code this time. about all I can find is it being related to the gas cap not being seated. Although I believe that an improperly seated gascap may throw some kind of evap code I am fairly certain this isn't my issue. I will triple check the gas cap as soon as I am done posting this, but what I am asking is where do I start looking if the gascap isn't the issue?

it's a code for a general evap failure. more than likely it's the ldp. it's just an educated guess from experience. though more testing would be needed to make sure

ldp? thanks for the reply.

leak detection pump