Cracked manifold with code 41
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
Cracked manifold with code 41
So after trying to figure out why my truck isn't able to get to 65mph, I found a massive crack down the middle of my passenger side manifold. I can hear it ticking as well. After pulling codes I only got code 41 which is system running lean. Could the cracked manifold lead to the o2 sensor indicating the system as lean and cause my truck to lose power when trying to reach highway speeds? It has great low end power though. Any thoughts guy?
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
A cracked exhaust manifold will trigger a lean code. The unmetered air is interpreted as not enough fuel so the computer keeps dumping in more to compensate. So in reality your truck is actually running pig rich.
A rich fuel mixture will kill a converter in short time. Almost worse than a true lean condition IMHO.
A rich fuel mixture will kill a converter in short time. Almost worse than a true lean condition IMHO.
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
I figured it would dump more fuel and technically run rich. Thanks for clearing that up for me bud. Would the issue cause me to lose power when trying to get accelerate if the crack is enough to throw a o2 sensor code?
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
Running rich kills power. It can ruin a converter in short order as well.
Is it THE root cause for your issue? Most likely. Replace that cracked manifold. You should also take a look at the converted while you are at it. A simple "rattle test" may confirm the converter is toasted.
Pull the O2 sensor to look for signs of contamination too. And the spark plugs.
Is it THE root cause for your issue? Most likely. Replace that cracked manifold. You should also take a look at the converted while you are at it. A simple "rattle test" may confirm the converter is toasted.
Pull the O2 sensor to look for signs of contamination too. And the spark plugs.
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
I pulled plugs 1 and 5, they aren't wet or anything. If the air fuel ratio is bad then it's not too bad. Gonna replace it this weekend to get my power back. I'm not worried about the cat. Gonna remove it when I get the chance and put dual exhaust or just one exhaust pipe no cats
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
Computer runs in open loop until the engine is warmed up.
Trending Topics
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
I was wondering if the truck would run rough even in open loop before the o2 sensor realizes there's a problem? If my exhaust is the cause for my problems then shouldn't it only cause loss of performance in closed loop after being warmed up?
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
Fix what you know is wrong. The EFI system is just that: a system. A single component supplying erroneous feedback causes the entire system to adjust.
You could spend weeks analyzing this or use the Easy Button. Fix what you know is wrong. One less thing in the equation. Do not ignore the obvious.
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
Long Term Fuel Trims are probably jacked to maximum values based on the O2 sensor readings over a period of time.
Fix what you know is wrong. The EFI system is just that: a system. A single component supplying erroneous feedback causes the entire system to adjust.
You could spend weeks analyzing this or use the Easy Button. Fix what you know is wrong. One less thing in the equation. Do not ignore the obvious.
Fix what you know is wrong. The EFI system is just that: a system. A single component supplying erroneous feedback causes the entire system to adjust.
You could spend weeks analyzing this or use the Easy Button. Fix what you know is wrong. One less thing in the equation. Do not ignore the obvious.
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
So know we find out the O2 sensor isn't even plugged in....https://www.ford-trucks.com/forums/1...into-help.html
That does not imply you do not have to repair/replace that cracked manifold.
By the looks of it whom ever replaced that engine for you did a very sloppy job. Hard telling what other easter eggs are hiding.
That does not imply you do not have to repair/replace that cracked manifold.
By the looks of it whom ever replaced that engine for you did a very sloppy job. Hard telling what other easter eggs are hiding.
Thread Starter
|
Elder User
Joined: Feb 2015
Posts: 510
Likes: 1
So know we find out the O2 sensor isn't even plugged in....https://www.ford-trucks.com/forums/1...into-help.html
That does not imply you do not have to repair/replace that cracked manifold.
By the looks of it whom ever replaced that engine for you did a very sloppy job. Hard telling what other easter eggs are hiding.
That does not imply you do not have to repair/replace that cracked manifold.
By the looks of it whom ever replaced that engine for you did a very sloppy job. Hard telling what other easter eggs are hiding.
Thread
Thread Starter
Forum
Replies
Last Post
itswillist
1999 - 2016 Super Duty
5
Aug 5, 2017 02:04 PM
DirtyFordTires
Escape & Escape Hybrid
2
Jul 30, 2011 06:34 AM
4.0 Beast
Explorer, Sport Trac, Mountaineer & Aviator
1
Feb 21, 2008 09:09 AM