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Discussion Starter · #1 · (Edited)
Some background info:
Bought my 2015 Ecoboom M6 at about 50k miles. I noticed since purchase sometimes at idle the RPM's will drop to about 600 and it will shudder for a couple seconds. I installed the updated LP fuel sensor and crankcase valve/hose. The car never had a CEL. I took it to Ford a few months before the warranty expired to get it looked over and they said they noticed some misfires at idle but claimed that replacing the head cover and gasket resolved it. Fast forward to two weeks ago. I finally upgraded my intake and intercooler, got a Cobb AP V3, and flashed an updated stage 2 tune. After a couple cycles or days I get the codes P0300 & P0316 read through the Cobb tuner. P0300 is apparently random misfire code and P0316 is misfire at startup.

I can usually go a few days and several cycles before these two codes triggers the CEL. My car is almost at 75K miles now. I just replaced the plugs with NGK 6510's gapped to .26 (for my mods). My car does not currently have a catch can (don't yell at me I'm broke). Current mods are MAPerformance IC and CAI.
On the stock tune, even with mods, my car does not throw any codes.
What you guys think? The car seems to run fine and better than ever with the new IC and intake. Will I have to get a custom tune to make these go away?

Update:
My codes are gone thanks to Ryan of PD Tuning. If you want to read about all the diagnosis I went through please read through this thread. My AP usually reads 0 misfires now when I start it. It looks like the codes were being falsely read by the canned tune's oversensitive misfire settings. Thanks to Ryan of PD Tuning for figuring this out. I'm looking forward to continuing to refine and tune the car.
Please note to anyone that comes across this: If you get these codes after tuning the car, don't listen to Cobb if they tell you that you need to clean your valves. I have yet to talk someone that actually had any codes thrown by dirty valves on these cars. If you're questioning it, have someone run a relative compression test on the engine.
Second note: If you find someone that will do a proper valve cleaning service affordably please let me know.

I'm still a little concerned about how my idle will sometimes drop to 500 RPM with the AC on full blast. But I'm going to attribute this to the leaky evap core. I've been refilling it with refrigerant for some time now to avoid replacing it ($1,000 cost)...
 

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Rough idle and that mileage may have coked the valve stems where they don't close properly. Start with plugs first and some fuel injector cleaner. If no better remove intake manifold and look at valve stems on intake side. If you get a misfire on one cylinder only could be coil pack going bad swap to different cylinder and see if it sets that cylinder to misfire, if yes replace coil packs
 

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Discussion Starter · #3 ·
Rough idle and that mileage may have coked the valve stems where they don't close properly. Start with plugs first and some fuel injector cleaner. If no better remove intake manifold and look at valve stems on intake side. If you get a misfire on one cylinder only could be coil pack going bad swap to different cylinder and see if it sets that cylinder to misfire, if yes replace coil packs
I have brand new plugs. Misfire is random misfire, no cylinder mentioned, and misfire at startup (first 1000 revs). Also have code for shutters being gone. CEL comes on after a while.
So you think I should try to do an engine cleaning?
 

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First make sure it isn't bad fuel. Run the tank low add in a good cleaner and 93 if you have it in your area. You stated they replaced head cover and gasket? Not sure what that means did they replace a valve cover gasket or the head gasket? what did the plugs look like that came out?
 

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Discussion Starter · #5 ·
First make sure it isn't bad fuel. Run the tank low add in a good cleaner and 93 if you have it in your area. You stated they replaced head cover and gasket? Not sure what that means did they replace a valve cover gasket or the head gasket? what did the plugs look like that came out?
Sorry the engine cover and gasket. This model year was known to leak oil. I’ve refilled a couple times already. The plugs looked OK. Shell 93 is all I use.
Is there any data logging I can do with the Cobb to help me troubleshoot?
 

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Okay so no oil leaking on plugs then. No misfire at higher rpms either right? when you say crankcase valve do you mean the fuel vaper hose assembly? Cobb allows you to data log but I am not sure what it will see at cold start up. Not sure what Cobb has for data logging. You want to look for ignition timing, spark and fuel pressure to see if something goes out of range. Also try some injector cleaner can't hurt. Part that can cause issues with start up is FR3Z-9G297-H
 

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Discussion Starter · #7 ·
Okay so no oil leaking on plugs then. No misfire at higher rpms either right? when you say crankcase valve do you mean the fuel vaper hose assembly? Cobb allows you to data log but I am not sure what it will see at cold start up. Not sure what Cobb has for data logging. You want to look for ignition timing, spark and fuel pressure to see if something goes out of range. Also try some injector cleaner can't hurt. Part that can cause issues with start up is FR3Z-9G297-H
No noticeable misfire at higher RPM’s. Idle does shudder occasionally, it drops 100-200 RPM’s for a couple seconds. I replaced that hose and LP fuel sensor when I bought the vehicle at 50K, about a year and a half ago.

I spoke to an ex-Ford master mechanic and he says these injectors can have issues around 60K miles. He’s claiming that regular fuel injector cleaner won’t be enough and that I should take the vehicle to Ford for them to do it.
 

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Could be carbon build up around injector could also be carbon build up around intake valves. See how much ford will charge and what kind of guarantee they give you. Might also talk to Performance shops that do engine mods rebuilds too see if they have come across similar issues and what they recommend. Direct injection tends to have more carbon related issues then the older style injector set ups. Injector cleaner may not fix it but it isn't going to hurt it either. Also you can pull intake and clean yourself, using walnut shell blasting or chemicals that brake down carbon and a wire brush. It doesn't have to go back to ford for that carbon cleaning. You have been doing everything right to correct it, also as you already know after this is resolved put on a catch can.
 

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Discussion Starter · #9 · (Edited)
An update. I called Cobb and they said I should be on the Stage 2 tune to remove the grill shutters code. Flashed to stage 2 and that code went away, but the P0303 & P0316 code came back the next day after a cold start, along with the CEL a little while later.
Cobb basically told me they didn't know why I'm getting those 2 misfire codes and that I would need to contact a pro-tuner.
 

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Saw your reply to my post and we have the exact same issue, P0316, P0303, and a grill actuator sensor code. I changed plugs to ngks and gapped them to 0.028. Still had my misfire codes and tried switching coil packs on cylinder 2 and cylinder 3 and was fine for a few days but came back this morning on my way to work. I assume we don’t know a fix for the issue yet but will keep updating what I’ve tried so you can eliminate ideas or not waste money on a working part on your end.
 

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Discussion Starter · #11 · (Edited)
Saw your reply to my post and we have the exact same issue, P0316, P0303, and a grill actuator sensor code. I changed plugs to ngks and gapped them to 0.028. Still had my misfire codes and tried switching coil packs on cylinder 2 and cylinder 3 and was fine for a few days but came back this morning on my way to work. I assume we don’t know a fix for the issue yet but will keep updating what I’ve tried so you can eliminate ideas or not waste money on a working part on your end.
P0303 is telling you something is going on in cylinder 3 specifically. P0300, the code I'm getting, is just a random misfire and not a specific cylinder.
If you've already swapped the coils and plugs on cyl 3 I'd try injectors next.

Stage 2 Cobb tune removes the grill actuator code.
 

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P0303 is telling you something is going on in cylinder 3 specifically. P0300, the code I'm getting, is just a random misfire and not a specific cylinder.
If you've already swapped the coils and plugs on cyl 3 I'd try injectors next.

Stage 2 Cobb tune removes the grill actuator code.
I went to a local mechanic yesterday who mainly does fords and specifically mustangs and he said atleast for me it could be bad oil or related to the cam but wants to do an oil change and a compression test to be sure I don’t need to take it to the dealer
 

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Discussion Starter · #13 ·
I went to a local mechanic yesterday who mainly does fords and specifically mustangs and he said atleast for me it could be bad oil or related to the cam but wants to do an oil change and a compression test to be sure I don’t need to take it to the dealer
Interesting. If it's an issue with the cam that could become costly. Please keep us updated.
 

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Discussion Starter · #15 ·
Will do I’m hoping it’s not the cam and that my oil just went bad quick and now it’s getting stuck on the cylinder on a cold start.
Oil doesn't typically just go bad unless a low quality oil/filter was used. A compression test is a good idea to make sure there's no boost leaks. But if it's that specific cylinder I would check the injectors first.
I'm interested to hear what the service tech finds.
 

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Stupid question you have the cold plugs gapped correctly and torqued to the right setting when you installed them. Also How many miles have your plugs done? More then 10k miles they need to be re gapped or changed, ideally changed.

I also strongly advise a custom tune. While many have success with the off the shelf tunes some cars, like mine did not like it, too much det, even in stage one. Now have custom and im golden. With well over 500 Nm.
 

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Discussion Starter · #17 ·
Stupid question you have the cold plugs gapped correctly and torqued to the right setting when you installed them. Also How many miles have your plugs done? More then 10k miles they need to be re gapped or changed, ideally changed.

I also strongly advise a custom tune. While many have success with the off the shelf tunes some cars, like mine did not like it, too much det, even in stage one. Now have custom and im golden. With well over 500 Nm.
I put brand new NGK 6510 plugs in when I installed the CAI, and intercooler less than 1K ago. Everything I’m reading, and experiencing (occasionally rough idle), seems to point to dirty valves.
Where did you get your tune?
 

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I put brand new NGK 6510 plugs in when I installed the CAI, and intercooler less than 1K ago. Everything I’m reading, and experiencing (occasionally rough idle), seems to point to dirty valves.
Where did you get your tune?
PD tuning. Lifetime tune. Also had back fire after FMIC install.
 

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So got my eco back from the mechanic today after getting an oil change. They looked over a few other things cause I asked them too and they pulled the plugs and saw the spark plug on cylinder 3 was soaked in fuel while the others were clean and dry. This could just be my own opinion but since cylinder 3 is the closest to the turbo the excess heat from the turbo could have caused the fuel injector to start failing resulting in it dumping fuel on to the spark plug. This would somewhat make sense atleast for my case as on cold starts there’s sometimes some white smoke coming from the exhaust. Has anyone checked to see if their plugs have fuel on them?
 
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