Ok. I'll do that. I'm also looking into these issues that I found on the web: https://www.700r4transmissionhq.com/p0440-chevy-s10/
Evap System Hose– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This will cause the P0440 code. Look for either a tear or hole in it. This is one of the most common issues that causes the code.
Vapor Canister Purge Valve– One of the most common causes of the P0440 code is the vapor canister purge valve. It’s really easy to replace. There are a few clips that you need to find and remove.
Faulty Charcoal Canister– The charcoal canister is often the cause of P0440.
Fuel Tank Sending Unit– It is possible for the gasket that goes between the fuel sending unit to the gas tank to go bad. This can reduce tank pressure and throw the code.
Fuel Cap– A bad fuel cap can cause the code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. If you are getting that message, plus a P0440, it may save you a ton of time and money to replace the fuel cap and see if it goes away.
Fuel Filler Neck– There is often a gasket where the fuel filler neck connects with the gas tank. This gasket can dry out, especially with vehicles that spend their time in dry climates. When it dries out, the fuel tank can’t hold pressure anymore.
I've already replaced the fuel cap and one of the hoses. These are the other places I need to look. I hope it's something easy!