4 and 7 are on the same siamesed coil, so I would not rule out coil issue for that one. 3 and 8 are not, but sometimes you get confounding issues. Swapping coils left to right could provide some insights.

 

Hmm.. So the Siamese aspect of the coils applies to top and bottom ports - not side to side. Maybe I’ll clean all the grease off of 4 and 7 first. And if I have to take the damn plenum off again, I’m replacing both coils - and probably ordering a fancy relocation kit (insert wink emoji). BTW, what hose needs to be modified for the relocation kit?

 

Short drive home and now it’s misfires on 1,2,3,4,7,and 8…

 

Did it shake badly at idle, or stumble while accelerating? A hard misfire does that. Or can you otherwise feel the misfiring while driving? Good to learn about O2 trends because if the trends are good, that means all the parts and pieces (sensors, valves, ECM, spark plugs, etc) are functioning well together.

 

You have to trim the hose on both sides if other Idle Air Control Valve. You can download the instructions and see all the photos during the installation process.

 

I fought w trimming the hose, and yes you can do that. But I would get a 7/8" ID hose from the hardware store. Something thinner and more flexible. In my case the nipple on the intake was close enough to the coil that combined with the thickness of the oem hose, it was really difficult to get it to fit. I shaved it down, grinded it thinner, cut it, etc. Ultimately it worked, but it would be a better use of time to just buy something more flexible. I was going to buy a new hose, but the time to modify the existing was shorter than a trip to the store. I still dont like how it pushing against the coil pack and I will probably replace it next time I go to the store.

 

I use OBD Fusion and it will chart fuel trim but you have to select it. The quick way is to go to the Logs menu and on the Graph screen select Menu at the top and then click the chart at the bottom. It will only allow you to pick four items to graph, but you can create multiple charts if you want (a little more complex). Change whatever the selected data points are (Coolant Temp, MPG, whatever) over to Fuel Trims and assuming the truck is running and you are connected, click Start and begin the drive. It should show the data in real time.

I prefer a more thorough approach to this which creates an exportable file and allows you to do a lot more with the data on a computer in Excel. First set up the data collection parameters by going to Settings<>Preferences<>Logging<>Select PIDs<>SAE PIDs. That's where the most important Data Sets are. You'll see multiple options on that list for Short Term and Long Term for the different banks. Make sure Logging Enabled is turned on on the Preferences tab. Once you finish the drive go to Logs<>Files and select the most recent log file from the list (assuming you have older ones), then select Share. You see multiple ways to get the file onto a computer. Open it in Excel and from there you can create graphs of the data. Here's what that can look like.

 

@Tony Luna Did you resolve the issue? I'm having some random similar misfires too (hesitation on launch, a wee bit of rough idle) and all related components are similarly in great shape, if not brand new.

 

Good thought but the problem with this is it is a very short radius bend and the factory hose is molded whereas most hoses you could buy commercially will be straight and no super easy to bend. Frustrating overall that LR did not give more thought to the coil situation but everything is a tradeoff. I looked at Subaru coils for the kit which have the plug wire towers horizontal instead of vertical and would have allowed side by side positioning, but that would mean all new coils AND all new spark plug wires which maybe some folks would have been ok with but I was thinking fewer. Looking at the market I saw very few people were willing to shell out the big money for the kit that moved them way over to the side, the kit was expensive, the wires were expensive, and if you ever damaged one getting a spare locally was going to be hard. Nothing is every easy is it.....

 

Except on a P38. The coils are actually fairly easy to get at on a P38.