P0300 Misfire code

I have searched everywhere and see many posts about the infamous P0300 Misfire code on our Shelby’s. After reading and seeing what people have tried, I too went through a lot of those things. The problem is with every thread I read, might even have multiple people with the problem, there is no conclusion or fix. I am hoping that all these people figured it out and just never returned to update their thread.

I am having this problem and want to correct it.
Mods:
JLT res delete tube
67mm TB
Pulley 2.4
Airaid filter
JLT Passenger catch can

Did you change your plugs in this process? I think sometimes a tight plug gap on a fresh set of plugs causes it and it ultimately stops throwing the code after a few miles. Just try driving it and see if it goes away. I never felt a miss while mine was throwing the random misfire codes, only misfires specific to a cylinder.

Thanks John. I have changed plugs three times. I think I will try one more time and open the gaps up a hair. I have been dealing with this code for over a year, almost to the day. It used to have a P0316 code with it but not this time. Went about 200 miles between this most recent code and the last time.

I was just hoping someone may have found a solution as most of the posts regarding P0300 was on this forum.

Love my car but she hasn’t been nice to me lately, this problem and the front end noise.

I thought I had heard that a loose crank bolt can cause a random misfire issue, maybe double check that.

can you feel the car physically misfiring? Who tuned it? Have you consulted them?

Zemedici said:

can you feel the car physically misfiring? Who tuned it? Have you consulted them?

Click to expand...

Slightly at idle but nothing horrible. I have spoken to my tuner who has been helpful. Unfortunately it’s been an ongoing thing for about a year. I wanted to see what others have found to maximize my chances of fixing this.

2011 gtcs said:

I thought I had heard that a loose crank bolt can cause a random misfire issue, maybe double check that.

Click to expand...

Even a stock never removed crank bolt?

Thanks for replying guys. I truly hope others can put up a conclusion to their problems as there were many people that started threads but never put a conclusion.

Just throwing this out there

Po300
Po316

Crank sensor

Have you tried a new sensor?

I also don’t normally throw parts at a car to fix but if you did have one for testing that be nice.

There where some notes in service manual about things that may cause false code.

I’m assuming you have read fords pinpoint test on these codes

hotcobra03 said:

Just throwing this out there

Po300
Po316

Crank sensor

Have you tried a new sensor?

I also don’t normally throw parts at a car to fix but if you did have one for testing that be nice.

There where some notes in service manual about things that may cause false code.

I’m assuming you have read fords pinpoint test on these codes

Click to expand...

I do not have a sensor but will get one as a last result or confirmation that it worked for somebody. I agree, I don’t like throwing parts at it either.

I have not seen the notes in the service manual that may relate to a false code.

I’m not sure of your definition or if that’s what they are called “pinpoint test”, I haven’t seen that but I have seen their description for those codes.

Tight Lines said:

Slightly at idle but nothing horrible. I have spoken to my tuner who has been helpful. Unfortunately it’s been an ongoing thing for about a year. I wanted to see what others have found to maximize my chances of fixing this.



Even a stock never removed crank bolt?

Thanks for replying guys. I truly hope others can put up a conclusion to their problems as there were many people that started threads but never put a conclusion.

Click to expand...

I would still double check the TQ on the crank bolt, I know it's extremely unlikely that it's loose but you never know, also checking the Crank sensor is a good idea.

Chilton Library
Scroll down open link in blue

Yr/make/model than hit select.

Next page click repair

hotcobra03 said:

Just throwing this out there

Po300
Po316

Crank sensor

Click to expand...

PO316 has the crank sensor as a possibility, but PO300's description refers to the camshaft position sensor. Neither is that expensive.

Intro

2014 PCED Gasoline Engines


SECTION 5: Pinpoint Tests



Procedure revision date: 10/10/2013




HD: Misfire Detection Monitor

Introduction


HD: Pinpoint Tests→




NOTE
Mechanical noise caused by the front end accessory drive components, mechanically driven cooling fans, or rough roads at high RPM with light load conditions may produce a non-symmetrical loss of cylinder acceleration, which may result in a misfire.





This pinpoint test is intended to diagnose the misfire detection monitor.

Clearing the powertrain control module (PCM) diagnostic trouble codes (DTCs) erases any PCM recorded freeze frame data. Make sure to record any PCM freeze frame information before proceeding. Refer to Section 2, Freeze Frame Data.


HD: Pinpoint Tests→

Listen
HD: Misfire Detection Monitor

2014 PCED Gasoline Engines


SECTION 5: Pinpoint Tests



Procedure revision date: 10/10/2013


HD: Misfire Detection Monitor

← HD: Introduction
HD1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
Are DTCs P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0309, P0310, P0313, P0315, P0316 or P1336 present?


Yes No
For DTC P0315, GO to HD21.

For DTC P1336, GO to HD18.

For all others, GO to HD2. RETURN to Symptom Charts, Symptom Charts for further direction.
HD2 VIEW THE PCM MISFIRE FREEZE FRAME DATA

• 
  The misfire freeze frame data may be used to determine the operating conditions when the misfire DTC was set.
• Retrieve and record any available misfire freeze frame data PID values from the PCM.
  
  
• Compare recorded freeze frame data PID values to the typical reference values in Reference Values, Reference Values.
  

Are any values out of range?


Yes No
REFER to the table in Pinpoint Test Z to find corresponding circuit, and PROCEED with the intermittent diagnosis.

GO to Pinpoint Test Z. GO to HD3.
HD3 RELATIVE COMPRESSION TEST

• 
  The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available.
• Carry out the Relative Compression Test. Refer to the instruction manual provided by the scan tool manufacturer.
  

Do all cylinders pass the test?


Yes No
GO to HD4. CARRY OUT a cylinder compression test on the suspected cylinder. REFER to the Workshop Manual Section 303-00, Engine System - General Information to diagnose the non contributing cylinder concern.
HD4 CHECK FOR OTHER NON-MISFIRE CONTINUOUS MEMORY DTCS

• Retrieve the PCM continuous memory DTCs.
  

Are there any non-misfire continuous memory DTCs present?


Yes No
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions. GO to HD5.
HD5 CHECK FOR ANY KOEO SELF-TEST DTCS

• Carry out the PCM KOEO self-test.
  

Are any KOEO DTCs present?


Yes No
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions. GO to HD6.
HD6 CHECK FOR ANY KOER DTCS

• Carry out the PCM KOER self-test.
  

Are any KOER DTCs present?


Yes No
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions. GO to HD7.
HD7 CYLINDER POWER BALANCE TEST

• 
  The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available.
• Carry out the Power Balance Test. Refer to the instruction manual provided by the scan tool manufacturer.
  

Are all cylinders contributing correctly during the power balance test?


Yes No
GO to HD9. GO to HD8.
HD8 CHECK THE IGNITION SYSTEM FOR CONCERNS

• For ignition coil on plug (COP) equipped vehicles, GO to JB4and follow the pinpoint test direction.
  
  
• For ignition coil pack equipped vehicles, GO to JC4 and follow the pinpoint test direction.
  

Is an ignition related concern present?


Yes No
REPAIR as necessary.

Clear the PCM DTCs. REPEAT the self-test. GO to HD9.
HD9 RELATIVE INJECTOR FLOW TEST

• 
  The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available.
• Carry out the Relative Injector Flow Test. Refer to the instruction manual provided by the scan tool manufacturer.
  

Are all injectors flowing correctly?


Yes No
GO to HD10.
CHECK for a loose connection, and damaged or corroded terminals. REPAIR as necessary.

GO to HD10.
HD10 CHECK THE FUEL SYSTEM FOR CONCERNS

• GO to Pinpoint Test HC and follow the pinpoint test direction.
  

Is a fuel system related concern present?


Yes No
REPAIR as necessary.

Clear the PCM DTCs. REPEAT the self-test. GO to HD11.
HD11 CHECK THE VACUUM SYSTEM

• 
  Some vacuum leaks can be heard.
• Visually inspect the vacuum hoses for signs of damage or deterioration. A collapsed vacuum hose may cause a blockage to one of the various actuators or sensors. If a blockage is found remove the blockage or install new parts as necessary.
  

Is the vehicle vacuum system OK?


Yes No
For Escape 2.5L,

Fusion 2.5L, and

Transit Connect 2.5L, GO to HD12.

For E-Series 4.6L, and

Mustang 5.8L, GO to HD13.

For all others, GO to HD16.
REPAIR the vacuum system.

Clear the PCM DTCs. REPEAT the self-test.
HD12 MONITOR THE EEGR SYSTEM RELATED PIDS

• Ignition ON, engine running.
  
  
• Bring the engine to normal operating temperature.
  
  
• Access the PCM and monitor the EGRMC1F (MODE), EGRMC2F (MODE), EGRMC3F (MODE) and EGRMC4F (MODE) PIDs.
  
  
• Access the PCM and monitor the MAP (PRESS) PID.
  
  
• Record the PID values with the engine idling.
  
  
• Ignition ON, engine OFF.
  
  
• Record the PID values with the engine off.
  
  
• Compare the recorded PID values to the typical reference values in Reference Values, Reference Values.
  

Are any values out of range?


Yes No
GO to Pinpoint Test KD and DIAGNOSE the EGR system. GO to HD14.
HD13 MONITOR THE ESM SYSTEM RELATED PIDS

• Ignition ON, engine running.
  
  
• Bring the engine to normal operating temperature.
  
  
• Access the PCM and monitor the DPFEGR (VOLT) PID.
  
  
• For E-Series with 4.6L 2V engine,
  
  
• Access the PCM and monitor the EGRPCT (PER) PID.
  
  
• For all others,
  
  
• Access the PCM and monitor the MAP (PRESS) PID.
  
  
• Record the PID values with the engine idling.
  
  
• Ignition ON, engine OFF.
  
  
• Record the PID values with the engine off.
  
  
• Compare the recorded PID values to the typical reference values in Reference Values, Reference Values.
  

Are any values out of range?


Yes No
GO to Pinpoint Test HH and DIAGNOSE the EGR system. GO to HD15.
HD14 RECREATE THE MISFIRE SYMPTOM WITH EEGR SYSTEM DISABLED

• 
  The PCM may store EGR system related DTCs during this procedure.To recreate the original conditions that set the DTC or caused the symptom, the vehicle may require driving.
• Ignition OFF.
  
  
• EEGR Assembly connector disconnected.
  
  
• Access the misfire freeze frame data (if available) and record the operating conditions.
  
  
• Obtain information from the customer information worksheet or any other available data from the customer.
  
  
• Recreate the misfire symptom using the freeze frame and customer information.
  

Can the symptom be recreated?


Yes No
GO to HD16.
REMOVE and INSPECT the EEGR for signs of contamination, unusual wear, carbon deposits, binding or other damage. REFER to the Workshop Manual Section 303-08, Engine Emission Control for more EGR system information. REPAIR as necessary.

Clear the PCM DTCs. REPEAT the self-test.
HD15 RECREATE THE MISFIRE SYMPTOM WITH THE ESM SYSTEM DISABLED

• 
  The PCM may store EGR system related DTCs during this procedure.To recreate the original conditions that set the DTC or caused the symptom, the vehicle may require driving.
• Ignition OFF.
  
  
• ESM connector disconnected.
  
  
• Access the misfire freeze frame data (if available) and record the operating conditions.
  
  
• Obtain information from the customer information worksheet or any other available data from the customer.
  
  
• Recreate the misfire symptom using the freeze frame and customer information.
  

Can the symptom be recreated?


Yes No
GO to HD16.
REMOVE and INSPECT the ESM for signs of contamination, unusual wear, carbon deposits, binding or other damage. REFER to the Workshop Manual Section 303-08, Engine Emission Control for more EGR system information. REPAIR as necessary.

Clear the PCM DTCs. REPEAT the self-test.
HD16 CHECK FOR BASE ENGINE CONCERNS

• 
  The engine temperature may affect the results.
• This step determines if there are any base engine concerns that may have caused the misfire DTC or drive concern.
  
  
• Ignition OFF.
  
  
• Carry out the following tests in order to evaluate base engine integrity:
  
  
• For vehicles equipped with mechanically driven cooling fans only, rotate the cooling fan by hand. The cooling fan should rotate freely, with no abnormal binding or interference. If binding or interference is present, remove any foreign materials or repair the cooling fan as necessary.
  
  
• Refer to the Workshop Manual Section 303-05, Accessory Drive and carry out checks in the Visual Inspection Chart.
  
  
• Refer to the Workshop Manual Section 303-00, Engine System and carry out the Compression Test and Cylinder Leakage Detection.
  
  
• Refer to the Workshop Manual Section 303-00, Engine System and carry out the Valve Train Analysis.
  
  
• Visually inspect the positive crankcase ventilation (PCV) valve and tube for leaks.
  
  
• Refer to the Workshop Manual Section 303-00, Engine System and carry out Component Tests.
  

Is a concern present?


Yes No
REPAIR as necessary. REFER to the Workshop Manual Section 303-00, Engine System.

Clear the PCM DTCs. REPEAT the self-test.
For DTCs P0300 or P0316, GO to HD19.

For all others, GO to HD17.
HD17 CHECK FUEL INJECTORS

• 
  For vehicles without the injector disable PIDs, follow the Yes answer.
• Ignition ON, engine running.
  
  
• Access the PCM and control the suspect INJ_OFF (MODE) PID.
  
  
• Command the suspect injector OFF.
  

Does the engine RPM change?


Yes No
GO to HD19.
CHECK the suspect fuel injector connector and pins for damage, corrosion or an incorrect connection. If no concerns are present, INSTALL a new Suspect Fuel Injector.

Clear the PCM DTCs. REPEAT the self-test.
HD18 CHECK THE CMP SENSOR

• Ignition ON, engine running.
  
  
• Access the PCM and monitor the SYNC (MODE) PID.
  

Is a concern present?


Yes No
A CMP sensor that is installed out of synchronization may set a DTC.

To verify the correct CMP sensor installation, REFER to the Workshop Manual Section 303-14, Electronic Engine Controls.

If the CMP sensor is installed correctly,

GO to HD19. GO to HD19.
HD19 CHECK THE GENERATOR FOR EXCESSIVE ELECTRICAL NOISE

• 
  If the generator/regulator is electrically noisy, the noise decreases when the B+ connector is disconnected.
• Ignition ON, engine running.
  
  
• Monitor the generator for an audible electric noise.
  
  
• Ignition OFF.
  
  
• Generator/regulator B+ connector disconnected.
  
  
• Ignition ON, engine running.
  
  
• With the engine running, determine if the generator is still noisy.
  

Does the noise remain constant when the B+ connector is disconnected?


Yes No
GO to HD20. REFER to the Workshop Manual Section 414-00, Charging System, and DIAGNOSE the generator is noisy symptom.
HD20 CHECK THE CKP HARNESS FOR INTERMITTENT CONCERNS

• 
  Damaged CKP wires or other physical damage to the harness may cause an intermittent short in the CKP circuit.
• Ignition OFF.
  
  
• Visually check for damaged CKP wires or other physical damage to the CKP harness.
  

Is a concern present?


Yes No
REPAIR as necessary.

Clear the PCM DTCs. REPEAT the self-test. GO to HD21.
HD21 CHECK THE PHYSICAL CONDITION OF THE CRANKSHAFT PULSE WHEEL

• 
  DTC P0315 is set when the PCM is unable to learn and correct for the mechanical variations in the crankshaft pulse wheel tooth spacing (the allowable correction tolerances are exceeded).
• Inspect the crankshaft pulse wheel for damaged teeth.
  
  
• Inspect the crankshaft pulse wheel for wobble.
  
  
• Inspect the crank pulley for wobble.
  
  
• Check for a loose crankshaft pulse wheel.
  
  
• Check the CKP sensor for damage.
  

Are the CKP sensor, crankshaft pulse wheel and the crank shaft pulley OK?


Yes No
GO to HD22.
REPAIR as necessary. REFER to the Workshop Manual Section 303-14, Electronic Engine Controls and check for correct CKP sensor installation. RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM).

For F-150 5.0L,

Fiesta 1.0L,

Fiesta 1.6L GTDI,

Focus 2.0L GTDI,

Mustang 3.7L,

Mustang 5.0L, and

Mustang 5.8L, COMPLETE the Misfire Monitor Neutral Profile Correction procedure using the scan tool.

For all others, COMPLETE the Misfire and Fuel Monitors drive cycle procedure to learn the profile. REFER to Section 2, On Board Diagnostic (OBD) Drive Cycle.

To verify the repair, RECREATE the original conditions that set the misfire DTC or caused the symptom using the freeze frame data and customer information. MONITOR the cylinder misfire data in Mode 6 - On Board Test Results and VERIFY the misfire count is below 10.

REFER to the scan tool manufacturers manual for specific information on the Mode 6 - On Board Test Results.
HD22 CHECK THE RECENT VEHICLE REPAIR HISTORY

• 
  Misfire Profiles stored in non-volatile memory may need to be relearned if major engine work is done.
• Check the recent vehicle repair history to determine if any rotational components have been replaced such as:
  
  
• crankshaft
  
  
• crankshaft pulley
  
  
• camshaft
  
  
• flexplate
  
  
• flywheel
  
  
• pistons or connecting rods
  
  
• front end accessory drive components
  

Does the vehicle repair history indicate any engine repairs for rotational components?


Yes No
For F-150 5.0L,

Fiesta 1.0L,

Fiesta 1.6L GTDI,

Focus 2.0L GTDI,

Mustang 3.7L,

Mustang 5.0L, and

Mustang 5.8L, COMPLETE the Misfire Monitor Neutral Profile Correction procedure USING the scan tool.

For all others, COMPLETE the Misfire and Fuel Monitors drive cycle procedure to learn the profile. REFER to Section 2, On Board Diagnostic (OBD) Drive Cycle.

To verify the repair, RECREATE the original conditions that set the misfire DTC or caused the symptom using the freeze frame data and customer information. MONITOR the cylinder misfire data in Mode 6 - On Board Test Results and VERIFY the misfire count is below 10. REFER to the scan tool manufacturers manual for specific information on the Mode 6 - On Board Test Results. GO to HD23.
HD23 CHECK FOR CORRECT PCM OPERATION

• Disconnect all the PCM connectors.
  
  
• Visually inspect for:
  
  
• pushed out pins
  
  
• corrosion
  
  
• Connect all the PCM connectors and make sure they seat correctly.
  
  
• Carry out the PCM self-test.
  
  
• Verify the concern is still present.
  

Is the concern still present?


Yes No
INSTALL a new PCM. REFER to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM), Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

• Intro

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
  
  
• Blocked 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 blocked or partially blocked.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test HD.

P0316 - Misfire Detected On Startup (First 1000 Revolutions)


Description: DTC P0316 sets in addition to any type B misfire DTC which occurs in the first 1,000 revolution test interval following engine start.
Possible Causes:

• Damaged crankshaft position (CKP) sensor
  
  
• Damaged ignition system
  
  
• Damaged fuel injectors
  
  
• Running out of fuel
  
  
• Fuel quality
  
  
• Base engine
  
  
• Damaged PCM
  

Diagnostic Aids: Freeze frame data and the DTC P03xx are also stored, indicating which cylinder the misfire occurred.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test HD.

Thanks hotcobra03. I will print this stuff out and go over it.

Tight Lines said:

Thanks hotcobra03. I will print this stuff out and go over it.

Click to expand...

Rely #10 had link to manual

There is a lot more to read before doing anything

I would also save what you can to a pc
Chitons library links get shut down a lot. Stupid laws but backdoors are always found.