I have a 2003 Expedition that has had service engine soon light on since I bought the vehicle (used). Took it to Autozone and codes indicated a MAF sensor. Tried using the aerosal MAF sensor cleaner and it didn't help. I replaced the MAF sensor and after about 5 starts the service engine soon light came back on again. Took it back to Autozone and it set codes P0102, P1132 and P1152. I tried to check EGR valve by pulling vacuum on it with hand pump and I could hear vacuum relieve when pump was disconnected, but haven't removed valve to see if it is stuck open, also don't know if EGR vave was holding vacuum or not. Listened to engine at idle, but could not hear any obvious vacuum leaks. If I remember, previous codes were indicating lean air mixture. Now after replacing the MAF sensor it is indicating rich air mixture. Any ideas?

Disconnect the negative battery cable for 30 minutes. Reconnect after and the code will clear. However if the problem persists, the code will come back with in 20 miles or 30 minutes.

It is probably going to be a misfire code, but I can't make any promisses. I would take it by Autozone or O'Reily's. They will scan it for trouble codes free of charge. The flashing light means you need to have it scanned urgently. It could be something pretty major so don't wait. Go now, your car will thank you:)

There is a diagnostic procedure in the factory service repair manual for engine light lit ,no codes . Did you take it to ford dealer ? MIL - is referring to check engine , service engine soon etc...

• MIL always on when engine is running (no DTCs):
• MIL circuits

• For Focus, Mustang, Town Car, Continental, LS6/LS8, Escape, Windstar, F-150, Expedition and Navigator/Blackwood:
• Instrument Cluster, Section 413-01 of the Workshop Manual.
• All Others:
• GO to NB1

SERVICE ENGINE SOON indicator After the engine is started, the SERVICE ENGINE SOON indicator will prove out for a duration of three seconds. If the instrument cluster does not receive a message from the PCM within five seconds, the instrument cluster will illuminate the SERVICE ENGINE SOON indicator and log a diagnostic trouble code (DTC).

• An indicator is inoperative/always on - SERVICE ENGINE SOON

• Circuitry.
• Bulb.
• Instrument cluster.
• PCM.

• GO to Pinpoint Test P .

PINPOINT TEST P: AN INDICATOR IS INOPERATIVE/ALWAYS ON - SERVICE ENGINE SOON CONDITIONS DETAILS/RESULTS/ACTIONS P1 CARRY OUT THE INSTRUMENT CLUSTER SERVICE ENGINE SOON INDICATOR ACTIVE COMMAND Trigger the HEC active command MIL.

• Did the SERVICE ENGINE SOON indicator illuminate?

Yes REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.

No INSTALL a new instrument cluster; REFER to Instrument Cluster . CLEAR the DTCs. REPEAT the self-test.

The service engine soon light indicates a problem.
Take the vehicle to AutoZone and have them read the computer code.
They can give you an idea of what the problem is and reset the light for you.
BTW the service is free

bring your vehicle to a local autozone (FREE) to have the computer scanned for the fault code. If there is no local autozone, check other car parts stores. Post the code/s here for further assistance!!

A lean bank 1 and 2 is indicating there is not enough fuel being injected to support proper combustion.
Leading causes can include but are not limited to......
1) low fuel pressure or plugged fuel filter.
2) vacuum leak causing lean condition.
3) air intake hose or crank case not sealed properly and bypassing the MAF sensor or the MAF sensor element is dirty.
4) wrong fuel or poor quality fuel used.
Hope this helps. If the Service Engine Soon light is illuminated, there will be fault codes associated the light. Get the vehicle scanned for free at your local Auto Zone or Advanced Auto and report back.

Generally this turn on when have any problem with the emission sensors; to know excalty what fault code there, make one scanned the PCM in autozone or autoshop with OBD Codes Reader.

With this code number we could send aditional details.

Hope helps (remember to rate and comment this).

If it has been serviced correctly just take it aback and ask them to reset the warnibg light. If they can't then you should chose another garage to service it.

Yes Autozone can check the codes for you for free.Both lights are on by design when there is a problem:)

bring your expedition to advance auto or autozone to scan your vehicle for the error code(its free) and post the code. Do you notice any drivable issues, such as rough idle, jerking motion etc??