Pulled the following codes: PO171, PO174 &PO307--I understand those and assume they're mostly part of #7 cylinder misfire, probably bad COP.

Also got: PO353, PO354, PO355, PO356 & PO358 which all refer to Primary/Secondary Circuit Malfunction, Ignition Coil C, D, E, F & H. What do these 5 other DTC's suggest? I've had one other COP fail and got the same or similar that once cleared never returned after installing a new COP.

Is something else failing or about to?

Thanks in advance!

 

Doing my own reply and follow up--------hoping it can help others.

I'd suspected either a bad COP or bad connection so first changed the COP with a known good one I had laying around---no change, still throwing various bad codes. A bit more poking around found the wire harness COP connector had lost its locking tab, wasn't making full contact unless I held it in place.

Since this was on Cyl #7 (2000 gas 5.4 E250) cutting, stripping and crimping a new connector into place was NOT an easy task--first time I wished I was left handed! After a few scraped knuckles and flying cuss words all seemed well.

Cleared all DTC's, test drive and no additional codes-----ran just fine.

The connector I found at NAPA, p/n EC259 for about $20 each----could be a common problem with the older connectors.

Hope this helps someone!

 

Thanks for the info!!!

Usually when you get both P0171 and P0174, it is either a dirty MAF or cracked PCV hose elbow causing a lean condition.

 

After driving about 100 miles on the repaired wire harness I got two additional codes still related to primary/secondary ingition which I assume is another minor wire harness problem. There has been a noticable rough idle when first starting in the mornings----shutting down then restarting immediately seems to self correct. This has to be just another minor wire harness issue.

I did notice the flexible air inlet piece just before the throttle body didn't have a snug fit for the two hoses that enter it, one from the left side valve cover and the other from the IAC valve. I'll replace this piece and hose, IAC line replaced during the summer. PCV valve, hose and elbow are all in good shape-----checked and replaced as needed also during the past summer.

As for the MAF what is the suggested cleaning procedure and solutions used? I've seen a few comments made about this and would like to try it myself.

 

I just use Brake parts cleaner. Just spray the filaments and let them dry. Do not touch them, they are very fragile and break easily. Carb cleaners usually leave a residue, brake cleaner does not. They also make a specific MAF cleaner if you don't have any brake cleaner laying around, just buy the MAF cleaner.
You should be able to spray it from the air filter housing end of the intake hose without removing the sensor.

 

Break clean is not recomened to clean a MAF it can leave a residue. They sale MAF cleaner at auto parts stores.

 

I wonder if this is the same issue I am having. New plugs and COP's and we get the WOT stumble. Also my wife drove the Excursion today and said that it "jerks" at 50-60 mph. I'm going to have to get a code scanner and check, it has to be throwing codes but I'm not getting the check engine light.

 

It could very well be throwing a code and the CEL bulb burned out? Not very likely but a decent code scanner that allows you to clear codes too is a great idea. I use an Actron CP9580 but you don't need something that elaborate for simple tasks.