EBPV Issue?

Hey Guys. Sorry this is long but I'm trying to be detailed to help with diagnosing.

Had 2 issues today after changing my oil today.

I changed the oil in my driveway after running some errands with the truck. Only reason I mention this is because it was in the mid to high 20s outside. I had the block heater plugged in and had let the truck warm up for 5 minutes or so before driving. I did not plug it back in while changing the oil.

I use 5-40 synthetic oil.

After changing the oil, it probably took 5-6 seconds on the initial start of the truck for the oil pressure gauge to show pressure. A couple of seconds longer than normal but I'm thinking that is due to the colder weather.

Taking the truck out for a spin in the neighborhood I noticed the engine intake noise drop to a lower pitch between the 1000 - 1500 RPM range and the truck didn't have the power it normally has. Only drove it about a mile and a half at less than 30 MPH. This lower pitched low power feel happened a half dozen times. When I pulled into the driveway and was in park, I tried holding the RPMs at 1500 but it kept dropping down to 1000-1200 RPM with the lower pitch.

I let the truck sit for about an hour. Went back outside and looked under the truck to make sure the oil drain plug wasn't leaking and noticed a bunch of diesel on the driveway.

I did not see where the diesel was coming from. I did see diesel in the engine valley beneath the filter. Diesel would not leak while idling in the driveway but after another quick spin around the block, diesel was running under the truck. I had changed the fuel filter 2 days ago so this was suspect. I had switched from a filter with the built in cap back to a filter without the cap. I did not see a new gasket with the new filter so I used the old gasket that had been sitting on the cap in my garage for the past 6 months. I was hoping this wouldn't come back to bite me. I guess that gasket was in bad shape or didn't seat properly. So I pulled the filter wrapper out of the garbage and found the replacement gasket stuck to it. Guess that is what I get for trying to do a job in a hurry. The weird thing though is there was not a noticeable diesel leak when I changed the oil.

I have read that the EBPV can behave in cold weather similar to what I am experiencing with the noise/low power. The funny thing is I did not notice this earlier in the day before changing the oil but the truck had been plugged in and it was warmed up before driving.

I think the EBPV is oil actuated. Is it possible that an oil pressure swing after the initial startup after the oil change could have caused an issue with the EBPV or is it most likely temp related? Could diesel spraying under the hood have caused a problem? While climbing around under the hood, could I have hit something? Or, am I experiencing something that is not EBPV related?

Thanks!