Wow! Great photos and a good pickup. This is Heatilator VP direct vent pipe. Yes, it is improperly installed:
-the horizontal firestop is not only installed upside down, thereby defeating the trayed spacer, which maintains clearances and is not fully nailed in place but,
-they used a wall firestop in a ceiling application. Note the 3" clearance at the top while there is a 1" clearance to sides and bottom. A ceiling firestop would have a 1" circumferential clearance.
-missing fireblocking per code
-missing insulation shield
-missing inside firestop at wall penetration. The one used at the ceiling should have been used on this wall
-heat shield not trimmed for wall thickness.
-hard to tell if done here but this pipe requires a 1/4" per foot slope up towards the termination.
-horizontal wall termination modified. See the little legdangling at the lower corner of this termination? That is where this box screws into the wall firestop--not hanging several feet unsupported out in the breeze.
-heat deflector on termination bent down. The sloped deflector should be at a 45 degree angle. By restricting the exhaust, it makes it prone to sooting inside the Fp. Very common with this termination. The mfr. shows the wall framed out with a minimum of 2x4s. This was 2x4 on the flat. It appears they melted the siding then modified the termination. I wonder if the inner section is even connected anymore.
Now for the good news--while all this should be torn out and replaced, Heatilator no longer makes their VP series vent pipe. If you supply them with the model and serial number along with the location where installed for their records, they might be able to scare up a transition piece to their current DVP series direct vent pipe along with a letter from tech services stating it is approved for retro fit.
Heatilator Fireplaces - Gas Fireplaces and Inserts They can also provide you with an installation manual stating the clearances and such.
More good news- the new pipe cannot be extended horizontally the way they have it configured. The remedy is simply to route it straight up through the roof using listed components and fireblock it with an attic insulation shield, too.
with all this mess, what does the facing look like? Remember what I keep telling you: when you see one goofy thing, you're bound to find more. Any more pics from inside Jon?
HTH,
Bob