P0440 engine code on my 01 Suburban

[ScottyBoy]

I am getting a SES light popping up. Checked the code and all that's popping up is P0440. Cleared the code and it came back on a few hours later. Replaced the gas cap since that's what seems to be the first thing that pops up on Google. Cleared the code again and it came right back on the next day. 2-3 days later the light went out by itself. I thought that perhaps the gas cap solved it. My feeling of success was short lived though, because after being off for almost a week, it came back on and has been on for 3 days now. What should I check next?

Not sure if this is related or not, but I have also been getting a hard to start condition every so often (cranks for about 8 seconds before it actually starts). This started shortly after the SES light started coming on. Its happened about 5 times now. Each time it happened, my truck was parked for at least
an hour. I was thinking FP regulator, but I thought if it was the FP regulator that I would have a hard start every time it sits for more than an hour. Its an intermittent problem. Could it still be going bad? Or could this be related to the P0440 code??

 

[Texas Jim]

My guess is you have a line loose from the charcoal canister or the purge valve is not working.

 

[Black02Silverado]

The purge valve sounds like an issue. I think that is next in line to be checked if the gas cap doesn't fix it.

My no start after the truck sat for a while has gone completely away since I put in a new fuel pump. It is nice to be able to start the truck right away and not have to turn the key off and then back on to start. How is your fuel pressure? I borrowed the fuel gauge from AutoZone.