5.0 with P0171, Rough Idle, Hard Starts - Clogged fuel filter?

[shadowless127]

So for the past month or so I've had some extra hard starts sometimes, but I chalked that up to the garbage AutoZone starter I have. Also have noticed that power is down, and when I give it the boot going up an incline it's really noticeable, regardless of how much fuel is in the tank. Lately I've noticed an occasional rough idle when coming to a stop but usually if I just sit there for 5-10 seconds it goes away for the remainder of my trip. Today the rough idle got worse, it would go away and then come back. Than tonight it throws a p0171.

My first instinct due to the hard starting, lack of power that is exponentially worse going up hill, and the rough idle is to assume it's a clogged fuel filter. Embarrassingly, I have never changed the fuel filter on this vehicle since I've owned it. I know, I know, complete rookie move. Am I right in assuming an old clogged fuel filter could cause this issue?

 

[JusTheUsual]

Could be. Running a fuel pressure test is a better idea but I still would replace fuel filter if you haven't yet

 

[The Captain]

I'm getting the same problem with mine. When I'm gunning it up a steep hill on the freeway my check engine light is flashing and im getting no power whatsoever. Also I can hear my Cats having post detonation from to much fuel getting trapped.

At first I thought it was my MAF sensor but it looks ok and I carefully cleaned it. Then I checked my wires but they seem fine.

 

[JusTheUsual]

Run a scan to see what codes it pops up? My cel light flashed at higher rpms because of a clogged fuel injector. When it flashes it is something terribly wrong

 

[shadowless127]

I'm getting the same problem with mine. When I'm gunning it up a steep hill on the freeway my check engine light is flashing and im getting no power whatsoever. Also I can hear my Cats having post detonation from to much fuel getting trapped.

At first I thought it was my MAF sensor but it looks ok and I carefully cleaned it. Then I checked my wires but they seem fine.

Flashing CEL means there's a misfire on one or more specific cylinders.

 

[shadowless127]

Went ahead and had the fuel filter replaced after work. Guy said it was absolutely disgusting. Noticed an immediate improvement in idle and power. Gonna run a bottle of fuel system cleaner and some techron in the next 2 tanks to clean it up a bit.