Notices
1999 - 2016 Super Duty 1999 to 2016 Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
Sponsored by:
Sponsored by: Real Truck

Rough idle

Thread Tools
 
Search this Thread
 
Old Apr 12, 2025 | 10:01 AM
  #1  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Rough idle

The engine strangling to stay running

I recently replaced oxygen sensors and converter because the engine will start and run good but quits running after I press the excelerator.

Since then i use the truck for several trips

I don't have CEL but I run diagnosing and came up with a code P0174 and P0420

​​​​​​​
 
Reply
Old Apr 14, 2025 | 10:43 AM
  #2  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Originally Posted by inventor
The engine strangling to stay running

I recently replaced oxygen sensors and converter because the engine will start and run good but quits running after I press the excelerator.

Since then i use the truck for several trips

I don't have CEL but I run diagnosing and came up with a code P0174 and P0420
wow no one have any idea what is going on the engine starts but is sputtering and strangling to stay on
​​​​​​​
 
Reply
Old Apr 14, 2025 | 10:59 AM
  #3  
crashz's Avatar
crashz
Mountain Pass
Liked
Loved
Community Favorite
Joined: Apr 2024
Posts: 221
Likes: 84
Not sure why it won't run, but doesn't trip the CEL. Both codes should trip that light pretty quickly.

I've personally found, and research here suggests that the trucks are very picky about catalytic converters. Most aftermarket units won't work. O2 sensors are a little more forgiving, but not by much.

Seems like two separate things on each side. I'd first check for exhaust leaks and loose connections. Something is causing that lean code and it might be the reason the truck won't drive. The Cat efficiency code may be just because the cats are aftermarket.

The only weird thing is that the CEL should be lit and the truck should start and run in closed loop mode. The stalling once you press the accelerator makes me wonder if the new cats (one or both) are plugged somehow??
 
Reply
Old Apr 14, 2025 | 02:16 PM
  #4  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Originally Posted by crashz
Not sure why it won't run, but doesn't trip the CEL. Both codes should trip that light pretty quickly.

I've personally found, and research here suggests that the trucks are very picky about catalytic converters. Most aftermarket units won't work. O2 sensors are a little more forgiving, but not by much.

Seems like two separate things on each side. I'd first check for exhaust leaks and loose connections. Something is causing that lean code and it might be the reason the truck won't drive. The Cat efficiency code may be just because the cats are aftermarket.

The only weird thing is that the CEL should be lit and the truck should start and run in closed loop mode. The stalling once you press the accelerator makes me wonder if the new cats (one or both) are plugged somehow??
OK thanks
I cleaned the codes I was told that if you do the repairs you must clear the codes to get it going, is the true/ correct?
I did not changed the downstream 02 sensor decause the truck run good long enough to get to the muffler shop 80 miles then the last 500 feet from home it started to die
no exhaust leaks fresh out the muffler shop
The truck was runing good on a new catalytic and two upstream o2 sensors dint change the downstream because she run good, now I order a new downstream o2 if that will fix I don't know
I order this one < https://a.co/d/gmZ2MNe >

 
Reply
Old Apr 15, 2025 | 02:01 PM
  #5  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Hey guys is it possible the stuttering/ choking is from the choke being stuck or not working?
I replaced the downstream o2 sensor that dint change anything, after warm up she idle at 600 rpm smoothly.
so why she stutter the first time i start the engine
 
Reply
Old Apr 15, 2025 | 03:04 PM
  #6  
crashz's Avatar
crashz
Mountain Pass
Liked
Loved
Community Favorite
Joined: Apr 2024
Posts: 221
Likes: 84
No choke on a fuel injected engine, but there is a throttle body. Doubt anything if going on there but maybe. The downstream sensors only measure the efficiency of the cats. So they shouldn't affect how the engine runs. I'm still stuck on something wrong with the cats which may be choking the exhaust flow. Seems like its too coincidental to have driving issues and these codes after a new cat install.
 
Reply
Old Apr 15, 2025 | 03:54 PM
  #7  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Originally Posted by crashz
No choke on a fuel injected engine, but there is a throttle body. Doubt anything if going on there but maybe. The downstream sensors only measure the efficiency of the cats. So they shouldn't affect how the engine runs. I'm still stuck on something wrong with the cats which may be choking the exhaust flow. Seems like its too coincidental to have driving issues and these codes after a new cat install.
No there no codes after the new catalytic install or since.
I order a new MAF maybe that is the problem?
 
Reply
Old Apr 16, 2025 | 12:03 PM
  #8  
V10superduty6.8l's Avatar
V10superduty6.8l
4th Gear
Joined: Apr 2025
Posts: 4
Likes: 0
I had a similar issue with all those codes I ended up replacing both upstream o2 sensor and then I also ended up getting a bunch of random misfires and I had to replace all my coil packs and the connectors as well. I don’t have a catalytic converter on my truck by the way. Also try cleaning your air idle sensor it’s at the back of the throttle body.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

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

 Brett Foote
story-2

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

 Michael S. Palmer
story-3

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

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

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

 Brett Foote
story-6

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

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Apr 16, 2025 | 01:54 PM
  #9  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Originally Posted by V10superduty6.8l
I had a similar issue with all those codes I ended up replacing both upstream o2 sensor and then I also ended up getting a bunch of random misfires and I had to replace all my coil packs and the connectors as well. I don’t have a catalytic converter on my truck by the way. Also try cleaning your air idle sensor it’s at the back of the throttle body.
no coils fule ingectors

 
Reply
Old Apr 16, 2025 | 02:31 PM
  #10  
inventor's Avatar
inventor
Thread Starter
|
Cross-Country
15 Year Member
Joined: Feb 2007
Posts: 87
Likes: 0
From: Arizona
Problem fixed

OK problem solved there was a small bug 🐛 fried in the MAF sensor, she runs good now
thank you all
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
DieselBulldog
1987 - 1996 F150 & Larger F-Series Trucks
6
May 4, 2024 10:00 AM
Jtegg007
2004 - 2008 F150
1
Oct 30, 2023 01:53 AM
Grendel's_virtue
1987 - 1996 F150 & Larger F-Series Trucks
5
Jul 28, 2022 07:42 AM
jarvisv77
Electrical Systems/Wiring
2
Sep 5, 2021 06:41 AM
Tady
Excursion - King of SUVs
0
Jan 21, 2018 06:02 PM




All times are GMT -5. The time now is 02:38 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