2001 Explorer 5.0 P0174 Code

[C420sailor]

Had a Triton 5.4 do this. Ran great open loop, went to hell once it warmed up and went closed loop. Threw bank 2 lean codes.

Chased all sorts of things. Threw plugs and coils at it.

Ended up junking it due to rot and other gremlins, but I always suspected that a rotting exhaust manifold on that bank was letting air into the exhaust stream, and throwing the oxygen sensor off. You got any exhaust leaks upstream from the O2 on that side?

 

[Turdle]

The 352 code is a bad wire or plug. Cylinder 2 on passenger side. 2 nd one from front.

 

[Exploder321]

This is a continuation of the P0174 thread... ( 2001 Explorer 5.0 P0174 Code ) Misfires on cylinders 3 and 5 (opposite sides of engine, same coil pack) and ignition coil B pri/sec circuit (If the 'primary' coil is #1 on the passenger (right) side, Coil B should be the driver side, so, same coil). I've tested with a HEI spark tester, no spark on 3 and 5 at the coil. 2nd set of coils (CarQuest Premium FWIW). I think I need to determine if the signal to the coil is present, but I can't find a break out of the coil connection as to which connector does what.

So far I've replaced the fuel injectors and connectors, intake manifold gaskets, MAF Sensor, Crankshaft Position Sensor, Throttle Pos. Sensor, EGR Valve and solenoid, PCV valve and grommet, and the PCM. I don't think it's the coils as they are new, the CKS could have been a bad source to the computer - replaced that. All that is left is the wiring harness? Or the PCM is bad (which I doubt as it is new)? The P0352 code was detected after the new PCM went in.

With the affected cylinders on opposite sides, that should rule out the O2 sens and possible exhaust manifold leak. Thanks again for your help.

 

[Turdle]

I've merged your threads, as the same problem persists. It'll help avoid redundancy,

You did not mention new spark plugs. If they are new, still could be bad. Use autolite or motoraft plugs.

352 is cylinder b which is 2

 

[Exploder321]

Thanks for the merge, considered going with the original, but the P0174 code has cleared. At any rate, new Motorcraft AGSF32FM went in at 227,600 mi., or about 23K mi. ago. I'm headed to the part store for a test light - no spark at the coil, need to figure out why.

 

[Turdle]

If you swap the 2 coilpacks side to side, get same code, that is a huge clue. Points to plugs.

If the code moves, it's the coils.

 

[allmyEXes]

Have you taken the wasted spark coil off and look at the bottom of it? Look for a split. I went through seven coils trying to find what was making them burn up. I ended up parking the 1997 Mountaineer 5.0. That is the favorite of the six Explorers that we own or have owned.

 

[Exploder321]

Both coils only have an hour or two of running time on them. I'm going to test the coil, and try to test for the switching signal from the PCM. This has been our favorite vehicle as well, I'd hate to have it fall prey to some kind of gremlin.

 

[Exploder321]

It would probably help to have better diagnostic equipment...

StackPath

 

[Exploder321]

Leading Causes Of Ignition Coil Failures​

Leading Causes Of Ignition Coil Failures

It may be surprising to learn that the leading causes of ignition coil failures have nothing to do with the coils themselves. Ignition coil damage is often caused by underlying issues never addressed in engine misfire repairs. Issues like spark plug gapping, leaking valve covers or moisture...

www.underhoodservice.com

Hmmmmmm.....

 

[allmyEXes]

@Exploder321 I don't know if this will help at all but this is what I went through before I punted. I hated to put the '97 MM 5.0 in the "penalty box" but it was costing me too much time, money and headaches. Now it has me part time consumed working to make it coil-near-plug with 1999 Crown Victoria parts.Link to original problem with the '97 5.0

 

[Exploder321]

allmyEXes, 6 pages on that thread, yikes! I'll look into that coil driver problem. I'm going to try my best to validate the signals and voltages going to the coil. Also going to replace the camshaft position sensor (a culprit in the diagnostic equipment article four posts up). There have been several failures identified since starting this thread, maybe I'll get lucky and find the coil killer!