Check Engine Light

beezerbiker · #1 10-09-2009, 10:19 AM

I have a 94 Ext Cab 4x4 with the 4.0L auto. Just bought it about two weeks ago, had 106k on it, I am the second owner, previous owner was an old man that lived on a dirt road so there is dust in everything but the interior. She runs perfect, everything works. But the check engine light comes on after a few minutes of driving. Its OBD one, so I can't take it to Auto Zone to plug it in and everyplace wants $90 just to tell me the code. I checked the Mass Airflow Sensor and cleaned it, I am leaning towards O2 sensors, any place else you guys suggest? She's a great truck, I plan on having her a long time, but that light drives me batty. Any help would be appreciated.
Thanks,
T

FireRanger · #2 10-09-2009, 10:41 AM

My first suggestion is disconnecting the battery to reset the computer. If the light doesn't come back on, pretend it never happened.

turbo · #3 10-09-2009, 11:44 AM

and the second suggestion is:

if the shop wants $90 to read the codes from your OBD-I system, do some online shopping and find an OBD-I tool to purchase... they're often found for quite a bit less than $90.

02'4.04x4 · #4 10-09-2009, 11:54 AM

Is there any difference in the performance/ sound of the vehicle?

Boujiboy2000 · #5 10-12-2009, 03:36 PM

Quote:

Originally Posted by turbo

and the second suggestion is:

if the shop wants $90 to read the codes from your OBD-I system, do some online shopping and find an OBD-I tool to purchase... they're often found for quite a bit less than $90.

thanks I have same problem with a 2001 engine runs fine but check engine light is always on

changed oil and all the filters and new sparkplugs, but the light still is on nonstop, I will look into the obd-1 tool just because I am a nerd though

Boujiboy2000 · #6 10-12-2009, 05:00 PM

Well I went outside and disconnected the battery terminals and took a wire brush and cleaned off the buildup of green cheese and reconnected them and the check engine light was not on. took it around town went to the local quickie mart for a mountain dew and on the way home i gave it a little more gas than usual around a corner and the check engine light came on again, I am guessing it is a dirty sensor, it has just over 100k on the odo and I just replaced all the filters and plugs.

thinking about purchasing this tool
http://www.amazon.com/AutoXray-EZ-Re...391324&sr=8-15

just because it is cheap and comes with a case so I do not damage it in storage.

all the info I have read says that all fords have been obd-II since around 96.

I hope im not wrong because I am going to order this tool

beezerbiker · #7 10-12-2009, 05:37 PM

A buddy has the tool, it says it's the EGR Valve. We'll see!!!!

beezerbiker · #8 10-13-2009, 10:22 AM

K, so took the sensor apart and cleaned it, tried to blow out the egr valve without removing it. Light still on. I noticed today that the idle is slightly rough, not bad, but a little jumpy so I am going to attempt the EGR vale this weekend. Shouldn't be a big deal, but it is so damned corroded I am afraid to screw with it. We'll see!!!!

Clem · #9 10-13-2009, 06:26 PM

This kinda goes with this post. I bought my truck new in 02 with 3.5 miles. At 18000 the CE came on, I am still waiting for the bulb to burn out.
Had it back to the dealer so many times we were on a first name basis, it has been to at least 6 different reputable mechanics and a couple of friends with scanners. The light is still on, reset it, it comes back on within 50 miles. For the last 2 years I have just left it alone and waiting for the bulb to die.
The only code that ever came up when it was scanned referred to an AC problem, yes it has been replaced, twice, AC worked before and still works.
So I wish you all luck at finding the problem, one of the dealer mechanics told me it was a problem with the computer, seeing as it came on so early in life and hasn't gone away. He wanted to sell me a computer, something over $600. Not!
The truck runs good and the mileage on the highway is 21+, so I am not complaining.
Ray

robsranger · #10 10-13-2009, 06:43 PM

i will say this much ce light in mine is on 96 3.0 scaned it said egr valve replaced it removed code after 10 miles came back on im now leaning toward my cat converter thats next step but dosnt make the truck run weird its a ford and im sorry to say i have had them my whole life and live by ford but they are known for CE light

Clem · #11 10-14-2009, 04:40 AM

I agree. I have had Fords from my first truck to present, when the CE lights were put into them I spent a lot of money trying to find out why the damn thing was coming on, mostly O2 sensors, and EGR valve problems. Get them replaced and the damn light would come back on within a few miles, so I got to the point, I would just watch the mileage and pay attention to the way it ran and pull the bulb.
Haven't got around to pulling the bulb on my Ranger yet, going to see how long it will last, (the bulb).

Ray

ranger324 · #12 03-10-2010, 06:57 AM

Quote:

Originally Posted by beezerbiker

I have a 94 Ext Cab 4x4 with the 4.0L auto. Just bought it about two weeks ago, had 106k on it, I am the second owner, previous owner was an old man that lived on a dirt road so there is dust in everything but the interior. She runs perfect, everything works. But the check engine light comes on after a few minutes of driving. Its OBD one, so I can't take it to Auto Zone to plug it in and everyplace wants $90 just to tell me the code. I checked the Mass Airflow Sensor and cleaned it, I am leaning towards O2 sensors, any place else you guys suggest? She's a great truck, I plan on having her a long time, but that light drives me batty. Any help would be appreciated.
Thanks,
T

My engine light is on also my friend had the diagnostic tool and it said it was the heater coil sensor so yours may be the same thing. My truck is running fine and the light has been on for almost a year, but it stays on continous.. you also may want to check your transmission it could be getting hot

Clem · #13 03-11-2010, 08:17 AM

I don't understand why you can't use Autozone? The local store does both OBD 1&2. Anyway, for about $30 you can buy an Innova brand code reader model 3145, it only works on 81-95 Fords. Comes with detailed instructions and diagnostic codes for a number of different Ford vehicles.

Ray

Bodyman · #14 05-25-2010, 02:35 PM

I think I might have fixed the 401 sensor problem. I took a razor knife and with the blade extended only slightly cut the top off the old sensor ,with a little prying,it snaped open and revealed tho holes. One labeled ref, I could blow thru the other labeled hi, I couldnt and its about the size of a needle. I took a needle and cleaned the junk out of it and hot glued the back back on. Seems to work after resetting the codes.