Codes 171 & 174 TSB # 03-16-1 update

[derffred]

p401 and p400 are both to do with your egr valve
here describes the P400

Answer to P0400 EGR FLOW MALFUNCTION
P0400 EGR FLOW MALFUNCTION is a blockage code, not a compenent failure. What the computer is letting you know is that something is preventing the EGR valve from opening and closing. A sensor mounted just above or near the EGR valve checks pressure to veryify that the EGR valve is indeed doing it's job. When the EGR failes to do it's job, that's when P0400 code surfaces. The typical cause of this code is cracked vacuum hoses or clogged hoses and or components with nasty carbon buildup inside of them. Each and every vacuum line to the EGR system needs to be checked! Carbon clogging also occurs inside the throttle body where the maze of vacuum lines originate. The task of unclogging those holes on the throttle body can become tideous, but needs to be performed in order to open up the vacuum flow. Rarely does a component failue throw a P0400 code, but when it does, it's one of three things. 1) EGR valve diaphragm is cracked and leaking vacuum, 2) The EGR plenumn sensor has failed 3)The amount of voltage getting to the sensor is not enough with a certain window, and will throw a P0400 code.


the p171 &p174 say system too lean but is often caused by a vacumm leak

you may also have blocked egr ports (under the upperi intake) see previous posts in this thread

[helmdoggie]

Alright I finally did the repair. I put new seals and the isolator bolts in, everything else looked ok. I went to the local ford dealer and bought the parts. They were about $84.00 all together. I want to thank everyone for their contributions to this thread. After reading through it a couple of times I felt like I had a good knowledge of the problem and knowing problems that popped up for other people. It was almost like I had done the fix before. I also used the lekemby website. For anyone that is thinking about doing this themselves, it is fairly easy. It looks far worse than it is. I numbered all of the wire harnesses and drew a picture of where all the vaccuum hoses went. (And by the way I still forgot to connect one, I found it after the test drive.)After you are past that it's pretty smooth sailing. I took the cowling off and it does give you a ton of space to work in. I used carb cleaner on a rag to clean the intake and mineral spirts on the plastic plenum. All in all it took me about 3 hours and that included lunch and a run to the parts store for a vacuum connector that I must have broke a couple of years ago when I replaced the power steering pump and mysteriously the heater/ac would only work in defrost. So acutally I fixed two things at once. My wife couldn't be happier. I was going to replace the plugs while I had the cowling off but after reading on this forum and looking at it I think its going to be easier to do from underneath the van. I guess my next fix is the front door lock. Thanks again to everyone.

[BoogiesAdda]

$324 is what i paid

[Tampabayer]

I have a 1998 Windstar ( 3.8L) and was getting those 2 codes PO171 and PO174 which turned out to be a small vacumn leak. Mine was right brfore my PCV valve. The rubber hose colapsed some and there was a little hole. It was constantly stalling out and running rough. After I replaced the 4 inch hose, I disconnected my battery so the PMC would be reset. Runs like a champ now.

[jmjax13]

This forum has been very helpful! Awesome!

I thought I would let you all know that my local O'reilly auto parts has a kit for the isolator bolt and valve cover issue. It contains all gaskets, isolator bolts (green sleeved), valve cover and gasket...this kit has it all...It cost me $97.99 plus tax....I just thought I would through it out there.

Hope this helps!!!

[garync1]

Originally Posted by jmjax13

This forum has been very helpful! Awesome!

I thought I would let you all know that my local O'reilly auto parts has a kit for the isolator bolt and valve cover issue. It contains all gaskets, isolator bolts (green sleeved), valve cover and gasket...this kit has it all...It cost me $97.99 plus tax....I just thought I would through it out there.

Hope this helps!!!

I paid 87.00 I think for my bolts and port seals and another 150.00 for the upper intake cover.. So you got a good deal..

[semcolil]

i went through a lot of crap for days on the 174-172 code...i finally took a fuel rail presure check found out my pressure was 21psi. min is 28. i changed the fuel pump and screen and never had the 174 172 code agin .the fuel system is not on the obd2 codes so i was getting a lean on bank 1 and bank 2 becaulse of low fuel pressure. i hope this info saves people more money and time than me. CHECK FUEL PRESSURE FIRST!!!1996 WINSTAR 3.8 AUTO

[jmjax13]

This is the kit like I purchased

http://www.1aauto.com/1A/-/GMC/-/1AEVC00013/

[joconnell]

I need advice on how to change the bearings or bushings on the front end.

[p15218]

I did the gasket bolt replacement about 2 years ago (2006) and last week the coolant pipe that runs over the intake manifold sprung a pin-hole leak. Apparently another common failure. Of course, the whole plenum has to be removed to change this part. If you're doing the ol' 171 / 174 fix on the plenum, you might want to consider replacing this #$&@* pipe. The pin-hole appears about 1" from where the pipe is connected to the intake manifold, facing foward, sprays towards the EGR valve.
Oh, and thanks again to the author of http://leckemby.net/windstar/windstar01.html as it came in handy again!
Bob

[Brandynr]

Figured I'd throw my experience with this TSB in here. I, apparently, was very lucky.

I bought a '00 Windstar used from a dealership in Feb. of '08. When I bought it, the salesman told me that the CEL was on, and that it was reporting the O2 sensors as being bad. I agreed to replace those on my own, and he knocked some of the price off.

Prior to purchasing the parts, I did my homework and discovered that the TSB was the problem, not the O2 sensors. Went back to the dealership, and they covered the cost of it completely.

My only question is, they did not replace the valve cover. Is this something I should do at some point? It's been a year since I had the work done, and I do not know if the problem will occur again or not.

[gasman1075]

Yes the valve cover needs to be replaced if you still have the old one
The valve cover is is a major part of the problem and you can tell if it has not been done with a visual inspection if you know what to look for check this web sight for the info,it has a ton of info on this TSB
http://leckemby.net/windstar/windstar01.html

Originally Posted by Brandynr

Figured I'd throw my experience with this TSB in here. I, apparently, was very lucky.

I bought a '00 Windstar used from a dealership in Feb. of '08. When I bought it, the salesman told me that the CEL was on, and that it was reporting the O2 sensors as being bad. I agreed to replace those on my own, and he knocked some of the price off.

Prior to purchasing the parts, I did my homework and discovered that the TSB was the problem, not the O2 sensors. Went back to the dealership, and they covered the cost of it completely.

My only question is, they did not replace the valve cover. Is this something I should do at some point? It's been a year since I had the work done, and I do not know if the problem will occur again or not.

[Brandynr]

Thanks. I'll have to get that done.

[visface]

I did the TSB fix and also replaced a leaky bypass tube, disconnected the battery. Runs great no codes but now my info center says CHECK COMP. Anybody know what CHECK COMP Means ?

[bulrid8]

I did the fix today. Not bad at all. Took about 2.5 hours to do. I bought the kit off ebay that came with all the parts, including valve cover. My EGR ports were clogged up completely.

Van runs like new again. Lets see if it stays that way!