P 0174, p0171, p0401 Problem solved
01-05-2009, 12:38 PM
#11
Notorious Thread Editor
Just wanted to leave some feed back on PO171 & PO174. I did the job in about 3 hrs. The throttle plates had a lot of varnish and carbon on them.
I would like to suggest:
8 (ea) "green" isolator bolts. Get them at FORD parts dept.
they can print you a IPB for referance
4 (ea) upper intake manifold seals, looks like figure 8's
a couple of cans of carb cleaner.
*optional upper plenum seal.
The isolator bolts seals had become "hard" and the upper intake manifold seals had allowed bypassing between chambers. to remove the isolator bolts flip the intake manifold over and use a 3/8" deep 1/4" drive socket to remove the isolator bolts. Tap them out gently. Once cleaned and reinstalled the codes haven't returned. I changed the plenem seal since I had everything opened up. Don't forget to torque the intake/plenum to manufactories spec's. Good luck
I would like to suggest:
8 (ea) "green" isolator bolts. Get them at FORD parts dept.
they can print you a IPB for referance
4 (ea) upper intake manifold seals, looks like figure 8's
a couple of cans of carb cleaner.
*optional upper plenum seal.
The isolator bolts seals had become "hard" and the upper intake manifold seals had allowed bypassing between chambers. to remove the isolator bolts flip the intake manifold over and use a 3/8" deep 1/4" drive socket to remove the isolator bolts. Tap them out gently. Once cleaned and reinstalled the codes haven't returned. I changed the plenem seal since I had everything opened up. Don't forget to torque the intake/plenum to manufactories spec's. Good luck
thanks for the good info
01-05-2009, 05:29 PM
#12
Senior Member
Congratts buddy, feels good to win one. How long did you wrestle with the firewall insulation? Seemed to me that was hardest decision, to cut the pad or not. The rest seemed to be just nuts and bolts.
06-06-2009, 06:46 PM
#13
1997 ford F150 4.6L ---- P0401 EGR CODE
Ok lisen up shade-tree mechs. I did EVERYTHING short of changing out the O2 sensors and the CATS and the "Check Engine" light still popped on. Low and behold it was a vacuum leak. Check behind the battery (most common place) for a leak. Mine was where the three vacuum lines gang together. The black line had a pin hole. This cleared my P0401 EGR Deficiency Code and it also repaired my air conditioner. My A/C would blow on defrost when I accelerated. Now the air comes out the panel vents like it's suppose to when I accelerate. Keep in mind I blew the cash on a new DPFE, EGR, etc and didn't have to. I hope this helps and you guys have been wonderful. Thank you and Godspeed !
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y2kdejesus (10-29-2017)
06-07-2009, 08:32 AM
#14
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While taking the TB off, I loosened a hose that had antifreeze in it, since the TB was loose already I'm afraid some antifreeze might have went into the lower intake... It's still apart as I need to go get a gasket to replace old worn one. What if anything should I do if water or dirt has fallen into manifold while I'm trying to remove TB? How do you take hose off with water gushing out right at intake hole? Where EXACTLY is the plenum and where and how many are the EGR ports? Are the four bolts that fasten the TB to lower intake the ones that have to be torqed? I took this loose because I've had banks too lean and insufficient EGR flow codes for about a year and yesterday I had a misfire on cylinder 1 to which the mechanic told me the EGR ports and plenum needed to be cleaned is what eventually causes the misfire on C. one. I relaced the COP and plug just to get back home and regretfully tried to remove and clean TB and EGR ports myself to save a couple hundred...It's a 98' F150 with 5.4
03-01-2014, 03:04 PM
#15
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Hi everyone i em new, i have be reading the post on the p0171 and p0174 codes. I have a 2002 f150 with the 5.4 with the same problem. I have check maf sensor,vacuum lines, intake gaskets all fine my truck runs fine but the fuel milage whent down, i have a freind at a ford dealer tell me it might be o2 sensors. I em going to put new ones in and see if it fixes my problem.
02-01-2016, 03:46 PM
#16
Junior Member
code 0174 temperature related?
I have the same problem. 2002 f150 4.2. 103K miles codes 0171 0174. I can reset engine check light in the summer and it will not come back on till November. If I reset in winter months code will be back in a couple of days. If reset in summer it will stay off. Temperature related? Anybody experienced the same problem?