Need Help With 99 WIndstar Check Engine Light ...codes p171 & p174...

[Dave 29]

The codes I got say running lean on bank 1 and bank 2....guy at parts source thinks its a vacuum leak. I took it to a buddy (backyard mechanic ) but very good at detecting these things Im told, he cant find a vacuum leak but he thinks its the intake manifold gasket....
any suggestions?
this is about a $400.00 job Canadian funds....the dealer is about double that Im told...
not sure what else it could be...he said the egr was working fine he tested it with a vacuum pump..did a few tests etc...
thanks for any input...
Dave

[DRW1000]

Do a search on this forum. There are endless amounts of threads on this issue and very likely your problem is the Isolator bolt deteriorization that causes an intake leak around the port seals.

[12Ounce]

If you do searchs here, you will find that many of us have had the same problem. Your mechanic buddy is close.... manifold gaskets .... and in particular, "isolator bolts" ... which are part of the gasket/seal scheme for the upper intake manifold. The isolator bolts have built-in seals that seal the manifold "spacer" to the lower metal manifold.

[grnf150]

I had the same thing on my 99. I have since cleaned the Mass Air Flow sensor in the aircleaner with brake cleaner and also replaced the left valve cover & pvc as indicated in the TSB listed below. It's been over a month with 800+ miles and no return of the codes. But still have a constant pinging problem.

The information on the following page has great detail on the TSB that was issued for this problem.
http://leckemby.net/windstar/windstar01.html

[Dave 29]

Thank you all for the help...
Dave

[Dave 29]

so you didnt replace the gasket set or isolator bolts?
thanks for any other tips..
Dave

Originally Posted by grnf150

I had the same thing on my 99. I have since cleaned the Mass Air Flow sensor in the aircleaner with brake cleaner and also replaced the left valve cover & pvc as indicated in the TSB listed below. It's been over a month with 800+ miles and no return of the codes. But still have a constant pinging problem.

The information on the following page has great detail on the TSB that was issued for this problem.
http://leckemby.net/windstar/windstar01.html

[DRW1000]

If grnf did not replace the bolts and seals my guess is that by cleaning the MAF it is now reading more accurately. Of course no more air is entering but the reading from the MAF is indicating that more is and a slight increase in fuel is calculated and delivered. Perhaps his seals are just starting to leak but not enough to register an error with the cleaned MAF. (but it did with the dirtyMAF) My guess is that he simply bought himself some time. I hope this is not the case for his sake.

[Dave 29]

what is a DPFE ? what does that mean if I order the part?
thanks

[ogre73]

DPFE = Differential Pressure FEedback sensor. It monitors the EGR system flow rate.

[DRW1000]

The DPFE is another common failure for the 99s and perhaps a few other years. It gives a different code or two. (401???) When you get this failure it is about a $70 part and 15 minutes to repalce so not a huge deal.

[grnf150]

Originally Posted by Dave 29

so you didnt replace the gasket set or isolator bolts?
thanks for any other tips..
Dave

Sorry for not getting back sooner .
Not yet on the isolator bolts or gasket. But I'm thinking I will end up doing it since it is still pinging.

[Goldlexus]

Originally Posted by grnf150

Sorry for not getting back sooner .
Not yet on the isolator bolts or gasket. But I'm thinking I will end up doing it since it is still pinging.

No guarantee that the isolator bolts will stop the pinging. I had the complete TSB done plus fuel injectors cleaned and tune-up. Still pinging it drives me nuts. Tried mid grade and high grade gas just a slight difference from using regular grade. Adding a gas additive has helped some. Also, having power issues sometimes it is gutless sometimes it is normal. PCM has been reprogrammed. ON top of that gas mileage stinks! Right after the TSB service my van had a definite power improvement and the pinging was gone but that last only a few weeks. No CEL. I hope it fixes your ping problem just wanted to tell you me experience.

[lewisnc100]

You might think about trying the Seafoam treatment discussed in another thread. It might remove enough carbon deposits to reduce the pinging.

[Goldlexus]

Originally Posted by lewisnc100

You might think about trying the Seafoam treatment discussed in another thread. It might remove enough carbon deposits to reduce the pinging.

I am going to expose my lack of knowledge of cars here, but where would there be carbon deposits? In the lower intake manifold? If so we had a new intake manifold put on at the time of the TSB this past August. I am probably totally confused on (acutally most likely) how all these things come together.

[DRW1000]

Carbon deposits inside the cylinder. This would effectively DECREASE the chamber size (in the head) and thus compression would increase. This could cause pre0ignition otherwise known as pinging.


Unless of course Lewis is refering to something else.

Are you getting a flashing CEL? indicating a misfire? This could be mis-described as pinging too.