'98 Volvo V70R

This is driving me crazy and CEL is on and need to pass emissions. I'd appreciate any advice on what I should look for, etc.

The code refers to a high voltage of the fuel tank pressure sensor. Easiest thing to do is see if there is power to the sensor, I did that, and then replace it, and I did that as well. I don't know if there is a way to test if it is really communicating with the computer. I was really hoping that would work, but no go.

So, am I correct to think that this could also be due to a vapor line or valve from the fuel tank being clogged? That could lead to an actual high pressure reading, right? I went ahead and replaced my purge valve (not the charcoal canister purge valve, but the one near the fan shroud) and pulled two gray/white one way valve in line, and they both allowed me to suck in one direction and not the other.

Since a vapor line goes straight to the charcoal canister, I thought that charcoal canister purge valve might be clogged. So I pulled the charcoal canister and I'm not sure where the purge valve is. I read that it could be of two different types, one is an electrical solenoid purge valve (don't see that anywhere), and the other is vacuum operated and is built into the charcoal canister unit (I think). I pulled my canister out and could freely suck on all holes (that sounds nice), but I don't know if this is correct.

Is there anything else that I could look for? Any other valves or ideas?

Thanks,

Wes L.
Salt Lake City, UT