Check Engine Soon light

[Butch Smith]

2003 Expedition 5.4L engine. My check engine soon light is on. Car is running fine. Is this a service reminder? How do I reset it? Thanks

 

[Butch Smith]

Anyone out there?

 

[rverdi]

It's not a service reminder, it's a notification that your computer is detecting a problem. Very often it is a gas cap that was put on improperly, so check that first. If not, a technician is going to have to pull down the codes to determine what's causing it. You may be able to reset it by pulling the negative battery cable for 30+ seconds but if the cause still exists, it's going to come back on.

 

[ELVATO]

Take it to Advanced, Autozone, etc and they should read it for free. Post the code on here.

 

[Butch Smith]

Must have been some bad gas. Filled up, started and stopped a few times and no more light. Thanks for the advice.

 

[rverdi]

More likely the gas cap was put on improperly at the last fill up. This time they put it on right and a few starts cleared the computer. Glad it worked out without a repair.

 

[ELVATO]

I would still stop by and try to get the code read. I think the computer keeps a log of codes, even after they've turned off. I'd check just to be sure.

 

[Butch Smith]

The light just came back on. Went and had it read P0136. Does anyone know what that means?
Thanks

 

[ELVATO]

http://www.obd-codes.com/p0136

How many miles are on your truck? Might be time to replace the O2 sensor.

 

[Butch Smith]

149000 miles