Long story short i yanked the 350 out of my 2000 Escalade and put in a 5.3 LS engine. My tuner said the fuel pressure regulator was hooked up wrong and was just dumping fuel into the intake. Took a look at where the fuel pressure regulator hose connects to on the intake, about 4-5 inches away, up and to the left, well that connector isn't there on my intake. So now my fuel press. reg. is just spitting fuel with no where to go and popped P0171 and P0171PD on the ride home tonight. I'm stumped. I have no clue what year the engine is, my "buddy" sold me a 5.3 that was anything but complete. I can take a picture if needed.

Any help is better than no help.

 

Sounds like the intake is at least 04 -up with no return line on the fuel rail.

You just need to replace the fuel rail with a 99-03 that has a return line to tie into the factory fuel system.

P0171 is Bank 1 system to lean.

Fix the fuel return issue and make sure the pump is putting out the right pressure.

Then make sure the intake is secured properly to the engine. The intake gaskets could also be bad.

 

The fuel line has the return style, not the intake. So i'd have to get a 99-03 intake with the return style connector on the intake, not the other way around. How do i check the fuel pump? Just check the fuel pressure at the adapter on the line?

 

It's the fuel rail, not the intake. The fuel rail is removable.

there is a pressure port on the Fuel rail, hook up a gauge there.