1997 Explorer XLT 4.0 L SOHC. Just happened tonight, the "CHECK ENGINE" light came on, the engine seems to be running OK. A quick check under the hood and I could not find any loose connecters, either vacuum or electrical. Can I check for the error code using some sort of iginition key on / off sequence or do I need some sort of test equipment. If so, is this engine equipped with an EEC-IV computer or OBD II? Is it safe to drive for a few days, mostly short trips?

 

Its OBD II , Youll need the proper scan tool .

 

I know that this may sound stupid but did you just get gas? If so, check the tightness of the cap. If the cap is not tight on some of these new trucks (I know that it happens on the Explorer) it can put the light on. Something about, the system has to be able to draw a vacuum on the tank. If it cannot it puts the light on.
Might not be your problem but worth 2 minutes to check!

 

Mine came on when the intake manifold seals were bad and covered under a separate warranty/recall...The other time it was my gas-cap not sealing which I'm seeing as a common first fix at the dealers....

 

My Check Engine light was on, engine was running rough, exhaust smelled funny, thought I had anti-freeze leaking into a cylinder. Found a source that listed the Fuel Pressure regulator as possible culprit. Put in a new one, engine ran fine and Check Engine light went out. It was a pretty inexpensive ($30) thing to try compared to bringing it in for a complete diagnosis ($70+).
The Fuel Pressure Regulator was located right in the front of the engine on top. Two clips on it and it was off and new one went in. I have a 1991 4.0 liter V6 (non SOHC).

 

Hello All,

Thanks for the inputs.
That night when I checked for loose wires and vacuum hoses the first thing I did was remove the gas filler cap and reinstall it. I ran the engine about 10 minutes and it (the check engine light) still remained on. The next day after about a 20 minuite drive, my wife informed me that the light went off. That was Saturday morning. As of this afternoon it still has not come back on. If it comes back and I figure out what caused it I'll update it here! Was it the gas cap and it just needed time to reset what ever sensor is there, I don't know.

 

I have had pretty good luck going to an autozone or something like that, and asking them to scan the code, which they do for free, and if it is a part that they have, i wil buy it from them. If it is a code that is not listed in their little book (ie. oem specific code) all i have to do is look it up on the internet (lots of sources)...I did this when my dpfe sensor went out on my 96 explorer..

 

Some of the OBD-II tests are only completed after an OBD-II drive cycle has been complete. An OBD-II drive cycle consists of starting with an enging that has cooled for at least 8 hours and then driving it under various conditions until complete warm-up. That is probably why your light didn't go off until the next day.

 

Hi. I feel as if I have hit the meca of information. Driveing on a long trip to Wisconsin from North Carolina, I purchased fuel about 50 miles east of Indy. Just North of Indy the "Check Engine" light went on. Overnight in Chicago, had to refuel North of Milwaukee.. After refuel, light went off.

All was fine until 1 month later. (last weekend) Drive from Durham NC to TopSail Island NC. (2.5hr drive) After stopping to get keys for a condo.. Light came on again and has not gone off. I was about 1/2 tank so I filled (bad choice I suspect) the tank with premium in hopes that if it were fuel, it would get the same results as the last refill... NOPE..

I have some slight soot around the tail pipe. Fuel economy is fine.

SO.. I can go to autozone (not one here) and get a diagnostic.. Or I can fork out the cash and get the diagnostic tool.. I don't have a problem with buying the tool since I intend to keep the vehicle. (any and all info about sources for reading the codes greatly appreciated)..

If the symptoms mean anything please let me know. Or, please give me your advice about how to diagnose.

Many thanks!

Chris

 

The first time, it was probably your gas cap. Either it was loose or for some reasone didn't seal properly. This time it can be any number of things and until you do get th codes read all anyone could do is guess. It is easy to guess when it is someone elses money For now go to Autozone if you have one reasonably close, otherwise try another similar place. Don't just purchase a code scanner on an impulse. If you are certain you want one then do your homework first to make sure you get one suited for you. I've seen them for around $100 that must interface to a laptop, $139 for a hand-held unit that will only pull the codes requiring you to decipher them using the included manual, to a $350 hand-held unit that gives a text description on the display and performs numerous tests.

 

Thanks for the response.. It must have heard me typeing about it because JUST this a.m. the light was off.. Bizarre...

 

It's back.. The light came back this afternoon.. I filled up with gas and adjusted the gas cap multiple times.. No dif. Off to Autozone at some point..

 

[font size="1" color="#FF0000"]LAST EDITED ON 07-Sep-01 AT 08:15 AM (EST)[/font][p]I the "amazing remote mechanic" will make a prediction......
...............
My Prediction is the "DPFE SENSOR" or Error Code P1400

Be sure to tell us what it was so i can bask in all my glory or
wallow in all my pitty......

 

P1110 Now I get to figure out what to do about it. Temp Sensor.. can you recommend a good source for what to check?

 

That would be your Intake Air Temperature sensor (IAT). It is located in the rubber intake hose that runs from your air-filter box to the top of your engine. Look at the hose and you will see a small device with two wires coming off of it. That is your IAT. If you can't find the wires, then the connector has fallen off or got pulled off. Look around for a loose connector in the area of the plug on your hose if it isn't plugged in. If it is plugged in, then try un-plugging it and plugging it back in incase it has a loose connection. Worst case would be having to replace the IAT which should be less than $50 (probably a lot less).