P0174 and P0171
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,507
Likes: 7,624
From: MI
I have the same codes. I'm still trying to find the problem. So far I've cleaned the MAF and smoke tested it. I will let you know when I find the problem.
These are some of the things I've read could be causing the codes.
Dirty or faulty MAF.
Vacuum leak, usually from the line you already replaced or from the manifold gasket.
Clogged or faulty fuel injectors.
I've addressed each of those issues. After cleaning my injectors and reinstalling them, my truck started and ran a minute or two and then died, I started it up a few more times and it would immediately die each time, now it won't even start. I'm thinking maybe it's just flooded, idk.
These are some of the things I've read could be causing the codes.
Dirty or faulty MAF.
Vacuum leak, usually from the line you already replaced or from the manifold gasket.
Clogged or faulty fuel injectors.
I've addressed each of those issues. After cleaning my injectors and reinstalling them, my truck started and ran a minute or two and then died, I started it up a few more times and it would immediately die each time, now it won't even start. I'm thinking maybe it's just flooded, idk.
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,507
Likes: 7,624
From: MI
Lean DTC's are fairly easy to figure out IMO. Start with the Fuel filter, then air filter seal/MAF o-ring, IAT grommet and intake tube/throttle body connection. Iac tube/breather tube. PCV system. Everything test good? Then replace your intake gaskets. The V8's chew them up, - right at both front water jackets.
Member
Joined: Nov 2014
Posts: 45
Likes: 2
Believe it or not my fuel pump had went out! I guess it had been on its way out causing some of my issues. Dropped the tank and replaced the pump and it fired right up!
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,507
Likes: 7,624
From: MI
