service engine soon light

service engine soon light came on after using cruise control. checked manual and it said there could have been a misfire. after 3 cold starts the computer could reset itself on the 4th start. did not wait for 3 cold starts and disconnect battery. light went out and i took the 98 windstar to DMV for inspection. it failed because OBD could not be read. need codes reset. Does taking terminal off battery reset code? Can it reset itself if there are no misfires? Van runs fine. Not rough or misfiring at all. I was down to a 1/4 tank of gas or less and just refueled. could this have something to do with it? or is this just the beginning of a long nightmare? How much is a code reader? could I get one at R&S auto?

Help

Check out the recent discussion between ModMech and DRW1000 on clearing the codes, there was some mention of failing since the OBD cycles hadn't been able to run since you recently cleared them. The discussion wasn't too long ago and had some good details that I can't remember off hand.

Maybe you just need to drive it enough to get the computer to run through all the checks before going back, assuming the code doesn't come back. Those guys should have more info for you.

You probably want to read the code(s). A good quality OBDII reader runs about 175-200 USD. You can take the van to some auto parts stores like AutoZone and they will read the codes for you. Either way, the tool also allows you to clear/reset the codes.

Many Windstars exhibit code P0171 and/or P0174 due to a poorly designed PCV system that gums up the intake manifolds. If this is the case a bit or work and expense in indicated.

Many Windstars exhibit code P0171 and/or P0174 due to a poorly designed PCV system that gums up the intake manifolds. If this is the case a bit or work and expense in indicated.

That is the case with 99+ Windstars, looks like the poster has a 98.

ooops, my bad. I missed the MY 98 in the original posting.

I am jumping in partway through this post but if you disconnect the battery terminals the codes are erased and the monitors are reset. In some states and provinces the vehicles can not be tested until all of the monitors have run their tests. There are flags that need to be set in the PCM that indicate that the tests have run. You need to take the vehicle through a couple of OBD drive cycles. They are described in your owners manual. If I recall correctly the most difficult one to run is the fuel vapour cannister test as it has to be above 4 degrees C (which it wasn't in March for me) and you have to start the car and get it to a certain speed within 30 minutes after an 8 hour rest.

a couple of days normal driving will do it in most cases.

You CANNOT "erase codes" by disconnecting the battery. All you accomplish is to dump the EECs short term memory and to re-set the adaptive tables. It might keep the CEL off for a couple days, (if it's an emissions performance issue), but other than that it will accomplish nothing of value.

Modmech is of course correct. What I meant to suggest was that it would clear the CEL (temporailly anyways) and the monitors. I always erased my codes using a code reader. I then have to run the monitor tests (at least my car does) before it is in a position to be eligible for an emissions test.

I also had a check engine soon idicator come on after refueling. I checked the manual, opened and resealed the gas cap, and the light did indeed go off after several (more than 3 or 4) cold starts. Shortly afterwards, though, the nightmare began...

The door sensors had been a problem for almost a year...boy did taking that fuse in and out upon every trip, for lack of a better word, SUCK. But it kept my battery alive. Anyway, on a 450 mile trip was when we had that first 'check engine soon' light. Then, about a month later, on a 100 mile trip, it came on again. This time, however, the van suddenly lost power. First the Tac fell to 0, then the speedometer fell to 0, then the jerking, sputtering, and loss of power, the clock was so dim you could barely see it, until it finally gave up the ghost and died in its tracks. We called our 'roadside assistance' number and while we were waiting, we decided to try to turn it over, and, much to our surprise, it started! We decided to try to get it home, or at least as close as we could, since our towing only paid for the first 50 miles. We got 45 miles from home when it died again. We were able to jump start it. It ran for a few miles. Jumped it again it ran a few more miles. We parked it at dad's. Put a new battery in it the next morning. It ran like there had never been a problem. No warning lights, nothing. Let it sit for two days, drove it about 40 miles with the heater, headlights, radio, and wipers on, same things shut off and it died again. Shut everything off, let it sit for 1/2 an hour. When it finally started, drove back with everything off, and it ran like a dream.

A few people have suggested that a new alternator is all that is needed...Does this sound right?

Definately can be the altenators not charging the battery. Take it to a local station and ask them to check the output amperage on it. should not cost much at all to check.

seems my heated o2 sensor is whats causing my SES light according to the OBD reader. PO156

thanks for all your help. found proper sensor and replaced with factory OEM. worked like a charm. Love my truck again.