one 171/174 resolution on rough running and stall

Read a lot on this forum after discovering it during a recent bad stretch with my 98 Windstar (3.8L, 144K miles) and 171/174 code diagnostic. Figured I'd detail my info in case others can benefit.

Problem started as extremely rough running when trying to restart after warmed up. Proceeded to dying anytime I would slow down quickly (like at stop signs and exiting freeway ramps). The check engine light was on.

Took it to a local guy I trust who is a goodyear owner and got the codes read at 171/174 "running lean" reading in my case. This was the point I made contact with this forum and figured it'd be a nightmare ... which was partially true. Even the diagnostic guy was finding it very difficult to pinpoint an exact problem given all the things that can be wrong under those codes. They were sensitive to the issue of older van how much money is too much to put in at this point. The only thing that stood clear was low fuel pressure 24 vs the usual range of 28-45 or so although 24 can still be marginal. Started with a change of the fuel filter and replaced a deteriorated PCV valve as low ticket items needing doing anyway. Didn't resolve the problem and more diagnotics including a smoke test machine that revealed some slight vacuum leaks but not enough to merit big bucks gasket replacement which was a possibility. Finally decided that the fuel pump was the likeliest culprit, replaced and it did resolve the problem. I thought maybe the CEL light would still shine on without affecting drivability (as it had may moons ago when there was a small split in a hose elbow), but even the light has disappeared and stayed off.

Judging from the forum I feel lucky to have gotten a reasonably problem free 140K out of it, but having also recently replaced the transmission, thinking I could get 200K out it (where my Honda is at) now seems wildly optimistic and I'm fearful this is the beginning of a series of account draining problems. ... but it seems too clean to just throw to the scrap heap. Anybody getting 200K out of a 98 Windstar?

I avoided my dealer on this since they've proven that they will recommend every treatment remotely possible cuz they have to pay for their new building makeover and expansion.

Hey.. I would first start off with pulling the intake plenum checking the seals and isolator bolts digging a little deeper go into and clean out your egr ports around the intake area. also check and clean your idle Air control valve. after a 140,000 miles I am sure its well over do.Also you said you changed the PCV valve but did the rubber groment that the pcv valve is pushed into look and good shape. If not replace. a vacuum leak will also cause the codes that you mention.Check all vacuum hoses and replace as needed it will cost a little but not to bad if you can do it your self. Yea stay away from the dealer as much as possable,but some parts you will need from them you can shop around and check online for those items.Hopes this helps and others will I am sure. I would also get a haynes manuel it helps alot.But this forum is great on letting you know whats most likley going on. Gary

I am glad you have solved your problem.
Another source for "how to" repair information is at www.autozone.com Look under vehicle specific repair guides.

I would run some fuel system cleaner through several times a year.

Make sure to change the transmission fluid every 30K miles......21K miles for "severe service".
An auxillary transmission cooler is a good idea also.

I am hoping to hang on to my '96 for a while longer....as, like yours....seems to be in good shape.

If your check engine light comes on....you can get the codes read for free at Autozone. Make sure that you get the Numeric code as well as the description of the failure.

Hey.. I would first start off with pulling the intake plenum checking the seals and isolator bolts digging a little deeper go into and clean out your egr ports around the intake area. also check and clean your idle Air control valve. after a 140,000 miles I am sure its well over do.Also you said you changed the PCV valve but did the rubber groment that the pcv valve is pushed into look and good shape. If not replace. a vacuum leak will also cause the codes that you mention.Check all vacuum hoses and replace as needed it will cost a little but not to bad if you can do it your self. Yea stay away from the dealer as much as possable,but some parts you will need from them you can shop around and check online for those items.Hopes this helps and others will I am sure. I would also get a haynes manuel it helps alot.But this forum is great on letting you know whats most likley going on. Gary
I PUT THIS in there so if you want to look into it later on.Maybe it would help you get past your 200,000 mile goal..I hope I get my 2001 there.I am at close to 80,000 miles on mine.

I agree with the EGR ports, etc....I cleaned mine for the first time at about 137K miles.
I would expect with TLC, (as any car requires for long life) your Windstar will serve you well.
Please post back with any problems that you may have....as there is a pretty good chance that someone else has had the same problem.

With your '98, you have a different upper intake manifold than the '99 and later years have.....and so the TSB for the isolator bolts does not apply to us with the older Windstars......the upper intake manifold that they used on the '96 through '98 years is a pretty rugged design.