An intermittent misfire has triggered several trouble codes

Intermittent misfire that sets multiple injector circuit failure codes. The codes are P0201, P0203, P0204, P0205, and P0206.

My car has 110000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi and thanks for your question. The codes P0201, P0203, P0204, P0205, P0206 are the cylinders that are not working. Your vehicle is only running on three cylinders that have fuel and possible fuel with the other cylinders at random times. Start the engine up and unplug on fuel injector at a time. If the engine begins to operate more rough than normal, then that injector is working correctly. If the engine does not change anything then that fuel injector was not working.

For each plug that you find is not working, check the harness for a voltage reference. If there is voltage, then the injector has stopped working and needs replaced. If there is no voltage, then get a noid light and plug it into the harness. This will check to see if the computer is sending signals to the injector. If there is no signal to the injectors, then there could be a break in the wiring or the computer could be damaged. If you need assistance in troubleshooting the misfire, then seek out a professional mechanic, such as one from YourMechanic, to help you with your vehicle.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

From the spark plugs to the ignition coils, many different things can cause an engine to misfire. The most common causes of misfires are worn, improperly installed, and mishandled spark plugs, malfunctioning ignition coils, carbon tracking, faulty spark plug wires and vacuum leaks.
CAR ENGINE MISFIRES

In severe cases, dirty fuel injectors can cause your engine to misfire. The misfire occurs when there`s difficulty with the air and fuel mixture entering the engine. This problem will usually cause the car to vibrate. You might even hear a jerk and pop sound.

Intermittent ignition misfires can be caused by faulty spark plugs, spark plug wires, ignition coils and ignition coil drivers located in the ECM.
Yes. While the damage may seem small initially, the longer you drive with a bad oxygen sensor, the worse the damage will become. Eventually, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emission tests.
The most common and relevant cause of a P0300 code is spark plugs that are damaged or worn. This is also a common cause among additional codes displayed as P030X. Spark plugs are devices that ignite the compressed mixture of air and fuel in each cylinder of an internal combustion engine.
Good quality fuel injectors rarely cause misfires whereas, poor quality or faulty injectors cause destructive misfires. The vehicle can experience various misfires when a faulty injector is a reason; it can lead to a loss in acceleration, power, and reduction in fuel efficiency.
No noise, intermittent clicking, or a difference with other cylinders likely means you have a bad fuel injector that needs to be cleaned, repaired or replaced.
Misfires that turn on the check engine light and log a cylinder-specific fault code are the easiest to diagnose. A flashing check engine light and a P0301 to P0312 diagnostic trouble code (DTC) is a surefire indication that one or more cylinders are misfiring.
Vacuum leaks, especially those that are confined to one cylinder, will cause the engine to idle unevenly and possibly misfire. This is because the vacuum leak allows additional air to reach the affected cylinder, diluting its air/fuel mixture.
A misfire on its own does not usually signal a serious mechanical problem. Very often, it is just a spark plug, ignition coil or a fuel injector that needs to be replaced. However, if you ignore the problem, more cylinders could start to malfunction, possibly to the point that the engine stops working entirely.
Generally, the cause of a misfire at idle is an incorrect air-fuel mixture. This can be caused by a faulty O2 sensor, a fuel injector that needs cleaning, or even vacuum leaks.
There are several types of engine misfires, including lean misfires, ignition misfires, and mechanical misfires.
There are several types of engine misfires, including lean misfires, ignition misfires, and mechanical misfires.
Many system malfunctions can cause misfires or rough idling. Ignition system components, including spark plugs, plug wires, ignition coils and ignition timing are culprits as are lean air/fuel mixtures and mechanical issues within the engine.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

An intermittent misfire has triggered several trouble codes
ANSWER : Hi and thanks for your question. The codes P0201, P0203, P0204, P0205, P0206 are the cylinders that are not working. Your vehicle is only running on three cylinders that have fuel and possible fuel with the other cylinders at random times. Start the engine up and unplug on fuel injector at a time. If the engine begins to operate more rough than normal, then that injector is working correctly. If the engine does not change anything then that fuel injector was not working.

For each plug that you find is not working, check the harness for a voltage reference. If there is voltage, then the injector has stopped working and needs replaced. If there is no voltage, then get a noid light and plug it into the harness. This will check to see if the computer is sending signals to the injector. If there is no signal to the injectors, then there could be a break in the wiring or the computer could be damaged. If you need assistance in troubleshooting the misfire, then seek out a professional mechanic, such as one from YourMechanic, to help you with your vehicle.

After i changed the crankshaft position sensor, i have a code p0302 which is a misfiring code.
ANSWER : The crankshaft and both camshaft position sensors should be replaced at the same time. Nissan had recalls on these sensors. Also, a simple compression test should be performed to verify no mechanical issues exist.

This car is known to have problems with the fuel injectors, this can be checked with a stethoscope to ensure they are clicking. Consider having a mechanic diagnose your car and replace your crankshaft and camshaft position sensors if necessary.

I have an intermittent misfire – 2002 Pontiac Grand Prix
ANSWER : Hi and thanks for contacting YourMechanic. The EGR can cause a misfire if it is stuck open when the engine is cold or running at a lower speed. The EGR replaces some of the air with burnt fuel to help cool the engine down, but when trying to accelerate, the engine will starve for fuel and cause a misfire.

Remove the EGR, clean it out and put it back on and retest the engine. I recommend replacing the EGR. If you need further assistance diagnosing the misfiring issue, then seek out a professional, such as one from YourMechanic, to help with your vehicle.

EGR code, Cylinder 4 misfire code 0304 detected.
ANSWER : Hi there. The Exhaust Gas Recirculation (EGR) valve may be not designed for the emissions requirements for U.S. standards. If the EGR is pulling from cylinder number 4 and after replacing the EGR and the computer detects a misfire, then the EGR is malfunctioning and not responding. When you close off the tube to the EGR and the EGR light comes on and the misfire light goes out, then the EGR is not responding to your emissions system. I recommend replacing the EGR with the OEM specified part for the engine and all of the issues should go away. If you need further assistance with your misfire and EGR, then seek out a professional, such as one from Your Mechanic, to help you.

One month ago cel came on I changed spark plugs to after market plugs. One month later cel on again with misfire code.
ANSWER : If the spark plugs hadn’t been changed until 130k, it was time for the to be replaced anyway. This is probably why the dealer went with that repair as worn spark plugs can cause misfires. Ignition coils are another part that may fail and cause misfires when they malfunction. A compression test and cylinder leak-down test will show if there is a problem with the valves. You can try having the coils replaced and the valves adjusted by the dealer. Consider hiring an experienced technician like one from YourMechanic who can come out and conduct the same tests as the dealer could and determine the cause for your check engine light.

I have a Code P0601 on the PCM. I replaced the PCM, and now I have a code P0118, code P0123, and code P0193.
ANSWER : Hi there, the short answer to your question is no . A PCM with a P0601 (which is a memory module error in the PCM) cannot reliably retrieve codes for the codes you list (P0118 – coolant temp sensor, P0123 – throttle position sensor, P0193 – fuel rail pressure sensor.

Most likely, the P0601 prevents the PCM from getting any codes from the engine sensors. The memory module error may cause in data corruption for collected sensor values, lose of data over multiple sampling periods, or failure of the data collection to work at all. Replacing the PCM was a necessary expense.

If you need assistance with the "new" codes, I would recommend having a Check Engine Light inspection completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose the new error codes and get an accurate assessment of the repairs needed.

Engine misfiring 2003 Honda CR-V
ANSWER : Misfires can be caused by several things. I would first check for vacuum leaks, then I would pull the plugs to see if they need replacing. It is possible that have a fuel system concern, but I would lean more towards a vacuum leak. The amount of air the engine intakes, is measured to ensure that the proper amount of fuel is delivered. If there is a vacuum leak, extra air that the engine is not expecting enters and causes the air/fuel mixture to be wrong causing a misfire. If you need help pinpointing the problem, a certified technician, like one from YourMechanic, will be able to diagnose the misfiring issue and help you move forward with repairs.

Misfire cylinders 4 and 7.
ANSWER : You need to check the PCV tube that goes behind the intake and connects into the back side. The hose can get a leak in it, causing a vacuum leak on the back side. This will create lean conditions that may be worse for cylinders 4 and 7 specifically on this engine.

If the hose is good then try and have the injectors replaced or cleaned for these two cylinders. You could swap them with different cylinders to see if the problem moves along to the other cylinder, doing so will help pinpoint the issue.

If you decide to get the car looked at, consider YourMechanic, as a certified technician can come to your location and diagnose your car’s misfire. An accurate repair can then be made once the problem has been pinpointed.