98 EXP Sport: MIL is on but no OBD code

[durk]

98 EXP Sport: MIL-CEL is on but no OBD code

My son's 1998 Explorer Sport has the check engine light on. A local shop ran an OBDII check for the MIL but there were 'no codes present'. Without a code we don't know what to fix. The mechanic suggested we disconnect the battery for a few minutes to reset the system and hope it doesn't come back. We did that but the check engine light has come back on again. Any suggestions how to isolate the problem? This is holding up an inspection sticker.

Thanks in advance.

 

[spindlecone]

Just a wild as guess, but a cat 02 sensor can throw a cel without a code.
If they hook you up at inspection, and see no codes, maybe you will be okay

 

[PS94]

Remove the bulb for the inspection?

Did you take it to Ford to pull the codes? It's more $, but they have some of the slickest tools for fords...

 

[durk]

Just a wild as guess, but a cat 02 sensor can throw a cel without a code.
If they hook you up at inspection, and see no codes, maybe you will be okay

I had a suspicion it might be the O2 sensor. It failed the inspection because the CEL was on even though there was no code. We have 15 days to fix it.

Thanks.

 

[durk]

Remove the bulb for the inspection?

Did you take it to Ford to pull the codes? It's more $, but they have some of the slickest tools for fords...

I don't know how to pull the instrument cluster. I actually have a bulb out on the left side I need to replace too. Any advice?

Hadn't thought about asking Ford to just test for the code. Just doing that much may not be so expensive.

Thanks.

 

[2000Sportdriver]

you can not pull the bulb, the inspection scan tool will regonise that the bulb has been pulled and ironcily enough throw a code.

Most Ford shops have the standard OTC tool, which comes out under several diferent names.

 

[durk]

you can not pull the bulb, the inspection scan tool will regonise that the bulb has been pulled and ironcily enough throw a code.

Most Ford shops have the standard OTC tool, which comes out under several diferent names.

Thanks for saving me from going down that rabbit hole.

This is my son's vehicle so I don't drive it. He just told me the heat guage stays on Cold. It looks like a thermostat problem. Would that throw the CEL on?

 

[sc012v]

If the CEL light is currently on, there is a code. Without a doubt. Who read it did not know what they were doing.

And even if the light went back off without the computer being reset, the code would be in the history (the history will be cleared if it is done manually or after X number of starts without a repeated out of range reading)

 

[gijoecam]

Indeed, the tool at the shop must not have wanted to fix it. If the light is on, there's got to be a code stored for it.

My guess is a failure to reach operating temp caused the engine to stay in closed-loop, killing the cats. Start with the thermostat to get it to come up to temp first.

Just out of curiosity, is it the check engine light, or check gauge light?

-Joe

 

[durk]

First, to answer GIJoeCam's question: it was the CEL.

It turns out the temp is OK. I took my son's word that it was stuck on Cold. In fact, it was operating normally. It just takes a few minutes to warm per usual. It's his first car and he is a little over cautious.

So, I took it to the local Ford dealer and asked them to re-run the diagnostic. They said they would charge me $100 for the pleasure. Needless to say I told them where to stick the tool.

I then took it to another local mechanic. It turns out it was a bad EGR valve. We had them replace all of the components and hoses at the same time and everything is ok now.

Thanks for everyone's help.

durk

 

[swetea1]

97-98 Mountaineers Not reading the OBDII Emissions Test! In Illinois they will suspend your license plate. Are any other people having these problems? I need to know fast; I have had catalyst convertors replaced: These are the codes that don't read:

CAT
CATHEAT
EAP
AIR
AC
02S
OS2Heat
EGR

Had the EGR pipe fixed also? Please help me. I have until 11/23/05 to get this resolved. They have already suspended my cousins' plate; has the same identical readings--

hit me at swetea1@yahoo.com or reply to this.