No aftermarket mods that I am aware of.
Would you run fuel system cleaner through it all or take it all apart and flush with ___???
Here's the Short but $$$ way. (best to have a helper)
Clean & Dry the tank REAL good.
Reinstall & Reconnect everything.
Buy 2/3 fuel filters. (to start with) (the $$$ part)
Put in 5 gallons of fresh fuel and a jug of fuel system cleaner. (per the ratio spec)
Open the Fuel Filter Drain Valve. (have a catch can inplace)
Turn the key on.. but Do Not Start The Engine. then....
Using a Shop Vac.. in Blow Mode.. put pressure on the tank to help prime the fuel pump, and lines, to purge any air out.. Pump til' you see fuel, no bubbles, coming out of the fuel filter drain valve.
Close the drain valve and Start the engine. (it may run rough but it'll clear up)
Drive it..... to go fill the fuel tank.
Then be ready to change fuel filters OFTEN.. until the fuel system cleaner.. cleans things up.
Joe
There's a cheaper way but it's more Labor intensive.