I had my fuel system cleaned by the dealership last weekend and I feel like I gained 50hp+

Now its throwing a P0171 about a week and a half later. My computer also listed P0174 under the pending codes or whatever the section was.

2003 F150 5.4L

I cleaned the MAF sensor a couple weeks back which stopped a rough idle and I have put some 300+ miles on it since. about 200 miles since the fuel system cleaning.

[edit]
I got home and poped the hood and it sounded like a vacuum cleaner. Guess it is a vacuum leak

[edit2]
I might need to stop using this ford house. I swear this is the second time there was a vacuum leak(I think, first time they said it was spark gap issue). I'll be heading back in the morning now.

 

Code 171 tells you it's a vacuum leak.
Maybe they introduced the cleaner through some hose or fitting and did not put it back on good.
Locate the source of the noise and you likely found the cause.
Good luck.

 

Very likely a vac leak, but also could be low fuel pressure. Check fuel pressure with a mechanical gauge. If you don't have one, auto zone will loan you one. You basically pay for it and then bring it back for a refund. They do this with special tools and some test equipment.

BTW, fuel pressure should be 35 to 45.