Notices
1997 - 2006 Expedition & Navigator 1997 - 2002 and 2003 - 2006 Ford Expedition and Lincoln Navigator Discussion

P0156

Thread Tools
 
Search this Thread
 
Old Dec 22, 2005 | 10:40 PM
  #1  
Nappers's Avatar
Nappers
Thread Starter
|
Senior User
Joined: Oct 2003
Posts: 124
Likes: 0
From: Northern California
P0156

Hey guys,

I have a 2000 Eddie Bauer Expidition with the 5.4. I ran my code reader and it popped up a P0156 code, meaning O2 sensor (bank 2 sensor 2). I am unsure which O2 sensor that is. How many O2 sensors on this beast (tried to decipher info on a search but with dial up it sucks) and would it be better to replace all of them? It has 75,000+ on it.

The gas mileage did drop about 4mpg and not running as smooth.

Thanks in advance.

Aaron
Nappers
 
Reply
Old Dec 23, 2005 | 09:46 AM
  #2  
FTE Herman's Avatar
FTE Herman
Post Fiend
Joined: Jun 2003
Posts: 5,983
Likes: 2
It is the one after the cat on the drivers side. There are 4 HO2S (Heated oxygen sensors) on your vehicle. Two that are in the exhaust stream before the cats, which are used to monitor the air/fuel ratio and two that are after each cat, which measure their effectiveness.
 
Reply
Old Dec 23, 2005 | 09:59 AM
  #3  
projectSHO89's Avatar
projectSHO89
Hotshot
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
The P0156 won't cause poor gas mileage, (HO2S2 is not used for fuel control) but the code can result from other conditions that do cause poor fuel economy.

If you have a misfire, address it first. It can cause excess fuel to be collected in the cat and keep the downstream O2 sensor from switching.

Other possible causes of a P0156:

An exhaust leak before the downstream sensor
Fault in wiring harness
Faulty sensor
Faulty PCM

Check your emissions warranty, some of these components are covered by your Federal warranty which, depending on where you live, could be an 8/80.

Replacing all four sensors would be a waste of money.

Steve
 

Last edited by projectSHO89; Dec 23, 2005 at 10:02 AM.
Reply
Old Dec 23, 2005 | 10:14 AM
  #4  
Nappers's Avatar
Nappers
Thread Starter
|
Senior User
Joined: Oct 2003
Posts: 124
Likes: 0
From: Northern California
Thanks guys, I can see the O2 sensor through the wheel well, may see if a wire broke, didn't hear an exhaust leak but will check it out. It's got 75,000+ miles on it and may replace and reset light and see what happens.

Thanks again.

Aaron
Nappers
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Janice44
Exhaust Systems
2
Mar 30, 2016 01:42 PM
Nappers
1983 - 2012 Ranger & B-Series
4
Aug 16, 2015 11:49 AM
77mud
1997 - 2006 Expedition & Navigator
5
May 27, 2014 07:29 PM
bluestang65
1997 - 2006 Expedition & Navigator
1
Jun 28, 2010 08:48 PM
luckild
1997 - 2003 F150
2
Mar 15, 2004 12:13 PM




All times are GMT -5. The time now is 07:09 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE