P0300/P0304 Misfires help!

[RR350]

From the '16 Helm:

P0300 - Random Misfire Detected

Description: This DTC sets when the misfire detection monitor detects an engine misfire in multiple cylinders or the PCM cannot identify which cylinder is misfiring.

Possible Causes:

• Damaged camshaft position (CMP) sensor

• Low fuel (less than 1/8 tank)

• Stuck open exhaust gas recirculation (EGR) valve

• Restricted EGR passages

• Misfire monitor neutral profile correction has not been relearned since the last mechanical repair

Diagnostic Aids: One or more EGR passages may be restricted.
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P0306 - Cylinder 6 Misfire Detected

Description: This DTC sets when the misfire detection monitor detects an engine misfire in cylinder 6.

Possible Causes:

• Ignition system

• Fuel injector 6

• Running out of fuel

• EVAP purge valve

• Fuel pressure

• Evaporative emission system

• Exhaust gas recirculation (EGR) system

• Base engine

• Misfire monitor neutral profile correction has not been relearned since the last mechanical repair

Diagnostic Aids: Misfire is defined as lack of combustion in a cylinder due to absence of spark, incorrect fuel metering, low compression, or any other cause.

The malfunction indicator lamp (MIL) blinks once per second when a misfire severe enough to cause catalyst damage is detected. If the MIL is on steady state due to a misfire, this indicates the threshold for emissions was exceeded and caused the vehicle to fail an inspection and maintenance tailpipe test.
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I think I have posted similar codes before. It might be as simple as an electrical pin connection...

Good Luck [MENTION=26503]RR350[/MENTION], please keep us posted.

Thank you for posting that info I really appreciate it. I will keep y'all updated, waiting to here something today. Hopefully it's just a sensor or connection etc.

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[RR350]

Service Manager just called. They ran the compression test, said cylinder 8 is reading 158 psi while 1-7 is reading 185+. Said they were going to start checking the valves, Rings etc. :shrug:

 

[Tank]

Service Manager just called. They ran the compression test, said cylinder 8 is reading 158 psi while 1-7 is reading 185+. Said they were going to start checking the valves, Rings etc. :shrug:

Oh man..Good Luck...

 

[americanmuscle1776]

Need some help guys. Just had my stock clutch and flywheel replaced at the dealership at 27,000 miles. My car for engine mods only has a JLT intake, Lethal Performance catless midpipes, and a Lund tune. I have had those three things done since the car had 5000 miles and never once had any issue. I also had the AC compressor and a few vacuum lines replaced at the same time as the clutch. I got the car back on Thursday and drove 100 miles home with no issue. But I took it easy on it, and didn't ever go above 4500 rpm. On Friday my friends and I decided to head to the canyons. It's about 60 miles to get where we were gonna start. Didn't go above 4500rpm heading there and had no issue.

As soon as we started going up the canyons, I went above 5000 and the check engine light started flashing. I pulled over and ran the code and came up with P0300, cylinder misfire. Didn't specify which cylinder. Thought maybe a fluke, so let it sit for 10 min, reset the code and took off again. Made it about 3 miles and again, as soon as I started going above 5k rpm, it came up flashing again. Ran it again and this time came up with P0300 and P0304, misfire on cylinder 4. So disconnected the battery, let it sit for 20 minutes to clear out any left over power, cleared the code and drove it home taking it easy on the highway with no issues on the way back.

My friend is a service advisor and I called him and he found this TSB. It doesn't have the GT350's listed, but has the exact issue I'm having. Guessing maybe our cars aren't listed because they are so new.

Has anyone else replaced their clutch and flywheel and had a similar issue? The second time I got the code, I disconnected the battery to see if it would reset and relearn, and then my friend sent me this pic and it states doing that won't work. I went through the NGauge to see if there was a setting where I could reset the KAM. I couldn't find it. I hope to find a way to fix this myself without taking it in, because I know if I do, as soon as they hook it up to the computers, it'll see my tune and flag my car. It has to be something they did, because before this past month it has been with them, I've had no issues in 27000 miles and I drive my car hard as shit.

My understanding is that when dropping the trans to replace the clutch and flywheel, that the crank can be slightly rotated throwing off the timing. It used to be that it could be relearned by disconnecting the battery, but now that doesn't work and it has to be connected to the IDS system at the dealership. Not sure on this, but that's how I read and have understood it.

Also, I'm thinking about swapping my spark plugs for some new ones. Anyone have any recommendations for some that won't break the bank or require a new tune? And this car only takes 8 I'm assuming right? My 2016 Scatpack Charger I have for my daily has 16 spark plugs.

Thanks in advance for any help. Hopefully this can help out some others too that are doing the same services.

What happened with my mustang

60K miles clutch started shuddering a little at first then horribly coming out of 1st and reverse

No matter how much gas you gave it or how quick you let the clutch out, it felt like when a beginner driver is learning to drive stick and stalls the car out—that kind of shuddering.

The ford dealership said it’d take 1 whole month for them to get to the repair on my car and that I’d have to leave the car with them for the entire month.

Obviously, I couldn’t go without a car for that long, so I did some research and found a highly rated private mechanic shop near-ish me.

They diagnosed the problem and installed a brand-new clutch and flywheel (regular ford replacement clutch and flywheel—i.e., not a fancy performance one)

No check engine light initially, within 24 hrs check engine light came on

Went to mechanic. Hooked up scanner #1 (Zurich ZR15S)

I took a picture of the code: P0304 (meaning cylinder misfire in 4th cylinder) to look up later even though mechanic told me not to worry about it.

I looked it up and seemed like it was potentially pretty dangerous

Did some research on ford forums and found discussions about people having had a similar error code (as well as other P03 codes for other cylinder misfires) specifically following clutch and flywheel replacement. These forums mentioned crank relearn and misfire monitor neutral profile correction as potential solution.

Went back within the hour with that limited info and mechanic was initially very hesitant to believe that that was the issue or the solution to the problem—he had never heard of a crank relearn on a mustang, he said.

Understandable: he’s reacting as a doctor would if you came in and started spouting off things you think are wrong with you from having looked at web md—i.e., he’s the professional and people who come in with that type of commentary usually have no idea what they’re talking about.

However, he looked on scanner #2, higher tech looking and didn’t see an option for crank relearn.

Might’ve been a snap on scanner (?), not positive on that, but it definitely looked more like this one:

Mechanic cleared code, said maybe it was a glitch since I wasn’t experiencing any engine misfire.

Went home. No problem till next day, check engine came back on.

Later that night, I actually felt the engine misfire (before I experienced it, I wasn’t sure exactly what that’d feel like, so I wasn’t 100% sure if I’d even be able to recognize it, but once it was actually happening, I knew immediately). The feeling was like a vibrating ratatat when depressing the gas pedal, and when I felt that immediately looked at the check engine light and saw that it had began blinking. That all lasted for about 10 seconds, then it was fine again, though the check engine light was still on.

So, then I was worried, so I did more research: texted mechanic that there was a lot of talk about check engine light problem after clutch and flywheel replacement on mustang forums. So, despite me not being a professional mechanic, asked him to look into it again with the key terms crank relearn/misfire monitor neutral profile correction.

See official ford technical service bulletin (TSB) outlining the problem:

Had car towed to shop just to be safe since I’d experienced an actual engine misfire the nigh before

He hooked up the Snap On scanner above and when I got there, he said he thinks I might be right. Cleared the check engine light, then ran the profile correction.

Link vid to people running that profile correction:





Been 2k+ miles and running like a top now, no check engine light has come back, and the car is running great. Note: for a few hundred miles (about 500 or so) after clutch and flywheel replacement, there was slight shudder (nowhere even near what it was like when I first brought it in) in shifting out of first and reverse. However, have read others experienced the same break in period post clutch and flywheel replacement, and shudder went away completely by 1k miles.

Turns out then whenever transmission is removed from engine, the computers inside the car need to be recalibrated.

See 2:06 for what it looks like when your transmission Is separated from the engine to access the clutch and flywheel for replacement:



Bottom line: super easy fix, just have to know about the “misfire monitor neutral profile correction” process and send them this doc/insist that your mechanic hook his scanner up and run it, even if he’s understandably skeptical because he’s never heard of it.

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