Help with CEL please

Thread Tools
 
Search this Thread
 
  #1  
Old 04-03-2009, 08:32 PM
cheezeonmakneez's Avatar
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Help with CEL please

Ok I have two codes coming up on my 97 with the 5.4. p0171 and p0174.
fuel bank 1 and 2 too lean. I cant figure this out at all. I have replaced the MAF sensor, fuel filter and spark plugs. all cylinders are firing ( unplugged each coil while it was running) and it still runs like its missing a cylinder. Anyone have any ideas?
Thanks in advance
 
  #2  
Old 04-03-2009, 09:01 PM
Matts ford's Avatar
Senior Member
Join Date: Nov 2007
Location: whaleyville, MD
Posts: 3,271
Likes: 0
Received 0 Likes on 0 Posts
check for a vacuum leak. especially the pcv elbow on the back of the intake. they are the most common reason for those codes.
 
  #3  
Old 04-03-2009, 09:03 PM
05crewzer's Avatar
Senior Member
Join Date: Jan 2009
Location: SugarLand
Posts: 1,005
Likes: 0
Received 0 Likes on 0 Posts
https://www.f150online.com/forums/v8...ions-list.html

check this thread. gives you a little info that might be helpfull also.
 
  #4  
Old 04-03-2009, 09:11 PM
cheezeonmakneez's Avatar
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Thanks alot. I'll pull it back into the garage tomorrow and see what I can come up with.
 
  #5  
Old 04-03-2009, 09:14 PM
Matts ford's Avatar
Senior Member
Join Date: Nov 2007
Location: whaleyville, MD
Posts: 3,271
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 05crewzer
https://www.f150online.com/forums/v8...ions-list.html

check this thread. gives you a little info that might be helpfull also.
you actually had enough patience to read all that? i opened it and just said no and clicked out of it
 
  #6  
Old 04-03-2009, 10:12 PM
05crewzer's Avatar
Senior Member
Join Date: Jan 2009
Location: SugarLand
Posts: 1,005
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Matts ford
you actually had enough patience to read all that? i opened it and just said no and clicked out of it
thats funny because i didnt read any further that po171......... and remembered that when this post came up. it didnt affect me so i past it.

but i knew it would help someone with problems with the same code. so heres my good deed for the day

hoped that helped you cheezy.
 
  #7  
Old 04-03-2009, 10:19 PM
cheezeonmakneez's Avatar
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 05crewzer
thats funny because i didnt read any further that po171......... and remembered that when this post came up. it didnt affect me so i past it.

but i knew it would help someone with problems with the same code. so heres my good deed for the day

hoped that helped you cheezy.
yeah me too. I'll find out tomorrow. Thanks again guys.
 
  #8  
Old 04-03-2009, 10:29 PM
jbrew's Avatar
Technical Article Contributor

Join Date: Oct 2005
Location: MI
Posts: 25,637
Likes: 0
Received 15 Likes on 15 Posts
When both banks test positive for lean, the most common problem is pin-holes or a tear in the PCV elbow that connects to the manifold back by the firewall.


 

Last edited by jbrew; 04-03-2009 at 10:32 PM. Reason: pics
  #9  
Old 04-03-2009, 10:42 PM
cheezeonmakneez's Avatar
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
awsome, thanks a bunch.
 
  #10  
Old 04-03-2009, 10:55 PM
05crewzer's Avatar
Senior Member
Join Date: Jan 2009
Location: SugarLand
Posts: 1,005
Likes: 0
Received 0 Likes on 0 Posts
kinda think jbrew knows what hes talking about. i would check that first
 
  #11  
Old 04-03-2009, 11:03 PM
cheezeonmakneez's Avatar
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 05crewzer
kinda think jbrew knows what hes talking about. i would check that first
thats what I have planned for the morning.
 
  #12  
Old 04-03-2009, 11:12 PM
jbrew's Avatar
Technical Article Contributor

Join Date: Oct 2005
Location: MI
Posts: 25,637
Likes: 0
Received 15 Likes on 15 Posts
Yea, service says to clean the MAF first, but it's usually the elbow. I would do both, - Clean the MAF if you haven't already and check the elbow. Any leaks in both PCV system and Air Intake system cause unmetered air. The PCM sees as lean resulting in the 71 and 74 DTC's.

There's other problems that could cause these codes - Like a dirty fuel filter or failing fuel pump, but it's usually the first one mentioned.
 
  #13  
Old 04-03-2009, 11:22 PM
cheezeonmakneez's Avatar
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jbrew
Yea, service says to clean the MAF first, but it's usually the elbow. I would do both, - Clean the MAF if you haven't already and check the elbow. Any leaks in both PCV system and Air Intake system cause unmetered air. The PCM sees as lean resulting in the 71 and 74 DTC's.

There's other problems that could cause these codes - Like a dirty fuel filter or failing fuel pump, but it's usually the first one mentioned.
well I just put a new MAF sensor and fuel filter on over this last week. I'm hoping to find vac leak.
 
  #14  
Old 04-04-2009, 12:35 PM
glc's Avatar
glc
glc is offline
Senior Member
Join Date: Dec 2006
Location: Joplin MO
Posts: 43,205
Received 763 Likes on 706 Posts
Aftermarket MAF may not have the right calibration.
 
  #15  
Old 04-04-2009, 04:14 PM
jbrew's Avatar
Technical Article Contributor

Join Date: Oct 2005
Location: MI
Posts: 25,637
Likes: 0
Received 15 Likes on 15 Posts
Originally Posted by cheezeonmakneez
well I just put a new MAF sensor and fuel filter on over this last week. I'm hoping to find vac leak.
What is she idling at ? Above 750 RPM's ? Is it loopy ?
 


Quick Reply: Help with CEL please



All times are GMT -4. The time now is 04:15 PM.