Pulled codes - now CEL is on???

[DZEE'S LX]

My idle has been a little more rougher than usual and the idle is surging a bit. Usually if I reset the computer things get better. This time the reset didn't do too much. So I thought I would check for codes. I have an EEC-IV reader that I used on my Ranger but I have never used it for the Stang.
So the code reader will initiate the KOEO testing but it would not return any codes. It is supposed to give me a 111 if there are no codes but I get nothing. The book says to check for bad connections and make sure the batteries are good in the tester. It also says that if the ground connector (the single pin) isn't grounded well enough that you should ground the connector to negative. Tried it but that doesn't help.

Now I notice that my check engine light is on even after the code reader is disconnected. The CEL goes out while the KOEO testing is running but as soon as I turn the ignition off and then back on the light comes on again.

What's up with this? I've never even had the CEL come on in my 8 yrs owning this car.

[~The Jester~]

Disconnect the battery, take the wife/girlfriend (NOT both!!!) to have breakfast.

Come back, reconnect the battery, you'll be good to go!

[DZEE'S LX]

Since I posted I tried that. Disconnedcted battery for about 30 min but the CEL is still on.
It's making me think that the ECU is still in self test mode for some reason. I wonder if it has something to do with the code reader initiating the KOEO test but not getting anything back.
I also found that when I ground the single terminal (like the book says) you can hear the self test run through the components, even when the code reader is not connected.
I'm getting more confused. I hope something hasn't been screwed up in the computer.

[DZEE'S LX]

Today I've been playing around with it more.
The CEL went out after starting it after the battery disconnect. (I had just turned the ignition key on last night and the CEL was on so I figured the battery disconnect didn't work).
Now the CEL comes on intermittantly. If I restart the engine it goes out but then eventually comes back on.
I figured I would take it to Autozone and have them use their code reader but the idiot at AZ had no clue of how to use th reader and he couldn't get any codes either.
I then drove around to a cuple other Autozones and Checker Auto places but none of them had a code reader for OBDI. Evidently all they do is OBDII stuff now.

So I read up in my Haynes manual about how to pull codes with a volt meter. They say to use an anolg meter with a needle but all I have is a digital unit. Will that work? It seems like a PIA to do it with the voltmeter so I'm just wondering if I should try it with my digital???

Anyone have tips for pulling codes this way?

[DZEE'S LX]

Update - persistance pays off ( or it was a couple of beers that did it...)
The code reader manual also mentioned corrosion that can affect the connectors. Mine didn't look too good so I cleaned the connector leads with a small piece of emory cloth and brake cleaner. Then as I was checking the wires through the plug I found that the continuity was shared between the two wires - so who knows what it was doing when connected to the reader. So I just cut the wires to the plug and wired it straight to the reader.
The test ran and I finally got my long awaited codes. Looks like I have a problem with the Canister Purge Solenoid - whatever that is - and an O2 sensor or circuit problem.
I can handle the O2 sensors. Too bad I don't have OBDII since I think that will tell you which one is.

Anyone know about this Canister thing...?

[mpj76]

The canister purge valve is used to purge the charcoal canister (black plastic box about the size of a 5lb bag of sugar that is located in the front bottom corner of the engine compartment on the passenger side). Just follow the lines and it should take you to it. I think its used to regulate the flow of evaporated fuel from the tank into the manifold since there's a vacuum line going to the canister from the manifold.