99 windstar misfiring

Recently, I have experienced some rough acceleration in between the 1,100 and 1,800 rpm range, after the engine has warmed. code description are as followes: oxy sensor bank 1 too lean, oxy sensor bank 2 too lean, cylinder 2 misfire detected. The vehicle is 80000+ miles and no corrective maint. has been performed yet. Any suggestions? Thanx, Jeff

What year is the Windstar?

What are the actual codes (numbers)? if you know them

Sorry I found the year..............

You may have clogged EGR ports and if the lean codes turn out to be the 171/174 codes you may have the all too very common Isolator bolt problem.

What year is the Windstar?

What are the actual codes (numbers)? if you know them

Codes are respectively p0171, p0174, and p0302. The engine is a 3.8L

Thanks, Jeff

ah yes the infamous codes. The bad news is that you need to do some work on your car. The good news is that there are many here who can help you every step of the way. If you are a backyard mechanic you can do this repair yourself. Parts should be under $100. Plan to spend about 3 hours.

Search this forum for:
171/174
Isolator bolts
EGR ports
TSB 03.... (something or other)

It has been discussed recently (on the 1st page or 2nd of topics). It also comes up every 2-3 weeks so there is a ton of info here.

There is a Technical Service bulletin (TSB) that addresses these problems. The TSB is on the site in a post as well.

You probably need to replace your isolator bolts and intake port seals as well as clean your EGR ports. This should clear all of the codes. You may also need to replace your fuel vacuum regulator if it is loose. The TSB also suggests replacing the valve cover as a preventative measure (which I refuse to do).


Do your reading and ask your questions. We will be glad to help.

Thanks for the help, Drw. Will do as you suggested. -Jeff

the TSB 03-16-1 procedure comments on reprogramming the pcm to the latest release. Is this necessary? If so, how to go about it. Thx, Jeff

You would need to take it to Ford for that.

I am not convinced it is nessesary but perhaps others may offer a comment. I have a theory that it sways the fence sitters into bringing their cars in for the TSB rather than doing the repair themselves and of course Ford is making a lot of money on this repair so the more the merrier (for Ford anyway). I am cynical though.

I did the intake repair on my '99 some 53k miles ago. Did not do the reprogramming. Did not know about it until fairly recently.
My engine will sometimes rattle a bit when under load, but otherwise does pretty well.... on regular fuel.

ok, thanks for the input. i'm doing to do the work first, reset the codes at the parts store, and see if any troubles persist. I'm a rather novice "backyard mechanic", but from what I've read it sounds doable. i am of the belief that learning comes from good advise from experienced people along with good 'ol as*holes and elbows approach. How else can you learn anything inexpensively? anything you guys can think of, that I need to do, that is outside of the tsb procedure? Also I would like to replace the fuel filter. Anything that I need to know or need any special tools?

Once again, thank you for the great input. Brgds, Jeff

I believe in torque wrenches. For this work you need a low-range wrench as the torques values are approx 8 ft-lbs. That's not much, but nonetheless best to have them uniform.

All of the torque specs I encountered were measured in in/lbs, not ft/lbs. I chose to purchase an inexpensive in/lbs torque wrench, rather than convert to ft/lbs.
I also had a subscription to Alldata.com, which gives you printouts right from the factory service manuals. Very helpful, and full of pictures that are much better then any of the parts store service manuals.
You do not need to take your van back to the parts store to reset the codes. all it takes is unhooking the battery. You will unhook the battery before starting the repairs, and the time it takes to complete them will be more than sufficient to reset the computer. I did this and have not had an error light since...

I finished the port seals and isolator bolt installation 8 days ago and so far, no codes!! I was surprised how easy the job turned out being. 3.5 hours and $91.00 later and all troubles were resolved. My plenum and upper intake ports were very oily; just cleaned with carb cleaner and a lint free rag. Incidentally, I had a free estimate of repairs done on the vehincle a day before doing the job (at the local Ford dealer). They insisted that my upper and lower intake gaskets needed to be replaced and the job, not mentioning anything about the TSB issues or accosiated parts, and would cost $550.00. So they mis-diagnosed the issues which subsequently, I would have blew $550.00 on non-issues.

Thank you sincerely to all that had helped with lending advice. You saved me a lot of dough for X-mas...!

Jeff