Sludge in the gas tank

About a day after filling up my gas tank my truck’s engine began to idle pretty rough and then later that day the engine would chug and have little power while going down the highway. The following day I stopped by my local mechanic and explained to him the problem. He took off the fuel filter, emptied it, and showed me all this black sludge coming out. Later he pumped out the fuel and found more black stuff. Even with a new fuel filter and clean gas the engine still ran rough. I went home and put all new spark plugs in and cleaned off all the carbon build-up around the throttle body. Right now the truck idles fine, but just doesn’t seem to have the power it used to.

Is there anything else I should inspect or replace after what looked like crude oil is pumped into the tank?

With that much gunk I suspect some passed the filter and into the injectors. Try a few tanks of fuel injector cleaner. Techron (? on spelling) is very good.