Bought a 06 heritage few months ago.
It's completely stock other than true dual python fishtails.
It had the baffles on it when I bought it and it missed and cut out until it warmed up.
I just took the baffles out now it never clears up and it pops on decel.

This is my 2nd Harley and first FI bike so excuse my ignorance but I know nothing about tuning.

What is the best bang for the buck route I can go to get this thing running right?

 

get an air cleaner and self-tuner -- cheaper than paying a tuner

 

A lot of people use Xied's available here. They are a simple enrichment device that is useful if you are just running high-flow exhaust. I used these on my Softail Slim when I was running slip-ons. After I upgraded my air cleaner and exhaust, I switched to the Power Vision tuner.

 

+1 concerning the Air cleaner. Investigate and determine if the previous owner installed a Stage 1, free flowing intake along with the duals. You would assume that he did but verify and identify the brand. Check out Dynojet's Power Vision. Great tuning device. User friendly, accurate, and flexible enough to accept any future engine mods.

 

How can I tell?

 

How do you know when it's tuned properly ?

I've built drag cars so I'm not dumb to tuning just never messed with FI.

 

Well apparently somebody that owned the bike before me went nuts on the filter backing plate.

Will this Arlen ness kit replace the broken plate?

 

Wow! That doesnt look right. Is it me or does that backing plate look more square than rounded. If it was me, I'd buy a whole new AC kit and cross it off the custom mods done by you list.

As far as best bang for the buck, there are a lot of options out there. Me personally, I'd go to FuelMoto. They have great deals with their billet stage 1 AC and power commander or power vision tuner. The best part is that you have great unlimited support and tunes.

 

To answer your question, yes that Ness kit will work. DKCustoms also has kits. FuelMoto as mentioned above has kits and tuners available as mentioned above. I run a HD Stage 1 kit that came on the bike and a FuelMoto PowerCommander III USB that they just remapped for me when I added different pipes. Their support is OUTstanding. Both companies I mentioned are site sponsors here and generally have specials for HDF members.
P.S. The looks of that backing plate could be one reason you're getting funny performance.

 

It looks to me like the guy I got it from broke it when installing the new cables instead of removing it.
Pretty crazy