Too Lean @ 12 mpg?

Reply Subscribe

Thread Tools

Search this Thread

Nov 8, 2006 | 02:23 PM

irulewhenshesnothome

Thread Starter

New User

Joined: Nov 2006

Posts: 20

Likes: 0

Too Lean @ 12 mpg?

I am getting a 171 code (too lean bank 1) and a 174 code(too lean bank 2) on my 1996 f150 4.9, 5sp with 110000 miles on it. I have done fuel filter, air ,oil, plugs ,wires,cap and rotor.

I am getting 12 miles per gallon.

Sometimes the idle rolls up and down.

PLEASE HELP

Nov 8, 2006 | 02:45 PM

andym

Post Fiend

Joined: Mar 2002

Posts: 19,402

Likes: 38

From: Bonita Springs FL

If you haven't ever changed your O2 sensors, this would be a good time to do it. It will most likely both your mileage problem and clear those two codes.

Nov 8, 2006 | 02:48 PM

irulewhenshesnothome

Thread Starter

New User

Joined: Nov 2006

Posts: 20

Likes: 0

I will check that out. I think my truck has two of them.

Nov 8, 2006 | 02:49 PM

irulewhenshesnothome

Thread Starter

New User

Joined: Nov 2006

Posts: 20

Likes: 0

Thanks, Just replace them both and hope for the best?

Nov 8, 2006 | 05:17 PM

EPNCSU2006

Lead Driver

Joined: Nov 2002

Posts: 9,557

Likes: 44

From: Concord, NC

Also try cleaning the heating elements in the mass air meter. The thin wires can get coated with dirt over time, causing the sensor to indicate less air than is actually going into the engine causing a lean condition. Clean the heated wires very carefully and very gently with a q-tip and some rubbing alcohol.

Nov 8, 2006 | 08:15 PM

sbowling79

Senior User

Joined: Oct 2006

Posts: 195

Likes: 0

From: Kentucky

do you know how to pull the codes without a scan tool I would like to check mine for any codes

Nov 8, 2006 | 08:37 PM

EPNCSU2006

Lead Driver

Joined: Nov 2002

Posts: 9,557

Likes: 44

From: Concord, NC

It depends on what year. The 96 is OBD-II which requires a code reader. If you have an older truck, you can pull them yourself. Run a google search for "eec-iv self test" and follow the instructions. Most of those pages will also have a helpful illustration of which wires to jumper.

Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

Verdad Gallardo

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Joe Kucinski

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Brett Foote

Top 10 Ford Truck Tragedies

Joe Kucinski

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

Brett Foote

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Michael S. Palmer

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Verdad Gallardo

10 Best Ford Truck Engines We Miss the Most!

Joe Kucinski

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Brett Foote

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Michael S. Palmer

Nov 9, 2006 | 10:16 PM

irulewhenshesnothome

Thread Starter

New User

Joined: Nov 2006

Posts: 20

Likes: 0

Today I replaced the o2 sensors and cleaned the air flow sensor with q-tips and alcohol. I drove 2 drive cycles and the light came back on. Same codes as before(171, 174). I checked ALL the vaccum lines and looked for leaks.

?????????????????????????????????????????????/
ANY IDEAS ?