2012 Spyder RS has a slight miss - any ideas/advice before I try a dealer?

[Rboggs]

A week ago I purchased a beautiful 2012 RS with 8800 miles on it. I noticed that it had a slight miss and I just can’t seem to figure it out. This is what has been done so far.
Changed vacuum lines on MAP sensor, check other lines.
New plugs and wires from Bajaron.
Multiple tanks of 93 octane fuel. I’m not even getting 120 miles out of a tank of gas. I could really use some advice before I have to pay a dealership a bunch of money I dont have right now. It idles pretty well for the first minute or two. I will include a video.
Well I can’t seem to attach a video.

 

[Jim's_Spyder]

I have a 2013 RS with about the same miles. Mine was missing really bad last year and this year it was unrideable. I pulled it apart today and I found dog food in the air intake. Mine sits in a heated garage and mice got into it and started making a nest in the air intake. I pulled it all apart today, cleaned out the dry dog food, changed the spark plugs, and checked the air cleaner. Luckily, other than some dog food and fouled plugs, I didn't find anything else. Yesterday, I had to trailer it home after I thought it was going to burn to the ground. It melted some of the plastic under the seat it got so hot from the unburned fuel in the exhaust. I store mine with a full tank with fuel stabilizer and have about a dozen mouse traps in my shop.
Mine was shuddering really bad on off idle acceleration, and missing at idle last year; the dog food was just an added bonus this year.

 

[Rboggs]

I picked up some carb cleaner today. I’m going to check the injector seals and the intake boots. After that I’m probably going to have to give in and take it to the dealership. I hate to pay all of that money when I know it’s probably something I can fix.

 

[CopperSpyder]

3 known problems with the 998 engines.

- There are two vacuum lines from the MAP sensor to the throttle body on the left hand side. Search the forum for pics and location. Just replace them now. 3mm ID silicon hose, cut the new ones exactly the same length as the old ones.

- Remove the charcoal canister and purge valve system. It's called a canisterectomy by the Spyderlovers community. Again, search the forum for how to.

- Replace spark plugs and wires. Get them from BajaRon

 

[Mikey]

That is really low miles for a 2012, it has not been driven much in its life! You're on the right track with the carb cleaner. Did you replace the fuel filter? CopperSyder made some very good suggestions that you have almost done to the tee, look into the purge valve! If you changed the plugs and wires, did you look the intake boots over good for cracks, make sure the wires are snapped down good! How did the air filter look?