Hello,

I have a 03 expedition with 91,000 miles on it. My check engine light came on and I took it to the auto part store and they gave me the following codes:

P0174
P0300
P0306
P0320
P0354
P0355
P0356
P0358
P0417
P0420
P0430

Any clues on what these are and where I need to start. Any help appreciated. Thanks!

 

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

 

I would start with interchanging a couple of coil packs...check you the Modular V8 forum, they can help you more...

 

First off.. Get a chiltons if you don't already have one and a Volt Meter... Reference the Chiltons for acceptable voltage information!

P0174 System too Lean (Bank 2)

Check MAF Sensor (Between Intake/Filter) for low voltage.. Clean MAF as that can possibly repair it. Also check for dirty fuel filter, possibly due for change.


P0300 Random/Multiple Cylinder Misfire Detected
P0306 Cylinder 6 Misfire Detected
P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction
P0354 Ignition Coil D Primary/Secondary Circuit Malfunction
P0355 Ignition Coil E Primary/Secondary Circuit Malfunction
P0356 Ignition Coil F Primary/Secondary Circuit Malfunction
P0358 Ignition Coil H Primary/Secondary Circuit Malfunction

Use the Chiltons and check Coil Voltages.. At 91k miles it's possible you have a dead Coil Pack or bad Coil Leads.. Standard replacement parts at that mileage.


P0417 Secondary Air Injection System Switching Valve B Circuit Shorted

No help on this one.. Not quite sure what they are referring to here. Sorry


P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0430 Catalyst System Efficiency Below Threshold (Bank 2)

Check for any exhaust leaks from Exhaust Manifold back. Use Chiltons and determine output voltage on O2's. This P code is normally bad O2's.. About 91k miles on factory O2 plugs is pushing it.. Chiltons will list the method to testing your O2 plugs and if they don't meet the recommend voltage, replace them. O2 should be roughly ~200mV flat.. If it flucuates then it's a dead Cat, if its stead but way ~100mV or less then its time to replace O2's.. Those two codes will be your Rear Sensors past the Cat's.. Not your Warm Up sensors.1

 

Refresh mah diesel intoxicated head.. 03 V8 Exp, they had Coil Pack versus Coil Over Spark right?

 

each individualy plug had its own coil right on top of it...not one spark plug wire...

 

Gotcha.. Wasn't refering to spark plug wire but more so the old Coil Pack method with lead wires to each plug.. I knew ford had moved to the Coil over plug method but wasn't sure when..

 

thats predominated used in GMs...buddy of mine with the avalanche and the 5.3L has what GM calls "A coil-near-plug ignition system"....zach should check in, he's the GM/Ford Guy...lol

 

Thanks for all the input....I guess I will start with the COPs and go from there....If I have any questions I will ask....I'm trying to do what I can without taking it to Ford. We will see. I will keep you posted.

 

Thats not quite all GM.. Some 4.6L Mustangs and the 02 F150 V6 I had used DIS and not COP.. So it's common, but I think more so select engines/vehicles.. None the less good info

Keep us posted

 

yeah...forgot about that....its the little block that takes the spark plug wires...the ranger we had had this...

 

Okay, I changed the COPs, used some seafoam, and changed the oil. I only have two codes which are the 420 and 430. So do I need to replace the oxygen sensors?

 

Hey Martin,

Tried emailing you back but it wouldn't let me.. Did you do a mV test on the O2's? If your not comfortable doing that then yes replace them.. Get a set of Bosch from Advanced, if it doesnt fix it you can return them.. But you should be good.. I almost doubt you have any wire chaffing, it's more or so just bad O2's.. About 100k miles is the normal replacement interval for O2's..

 

Thanks....I'll try replacing those. Are these hard to get too? I want to do them myself, I guess I will look at the service manual I got or at ALLData to see where they are located.

 

What's a MV test?