Multiple misfires on 2000 honda acroed just replaced the plugs what would cause a mis fire on all 6 cilders

U need a new coil. They wear out from heat and age. Also bad plugs put strain on it cause they draw to much currant

the misfire could also be the coil that is what send's the spark to the distributor, if it is weak it will cause a random mis fire code for any cylinder, the plug wire's on my 2000 xterra are numbered it will be the second plug on the driver's side of the engine, the cam sensor will also give a mis fire code if it is malfunctioning, I have a 2000 xterra that is a night mare when it come's to code's and repair's it is not alway's the first thing you think with these vehicle's, try to change all the plug's and dis connect the battery for 20 minutes then hook it back up and run down to your local autozone or pep boy's and have them hook up an OBD to see if it is fixed or if another code appear's

Im assuming your asking about the ODB-II codes, this code,P0300 Random/Multiple Cylinder Misfire Detected.
A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.
Here are a few things that could be the cause.

Faulty spark plugs or wires

Faulty coil (pack)

Faulty oxygen sensor(s)

Faulty fuel injector(s)

Burned exhaust valve

Faulty catalytic converter(s)

Stuck/blocked EGR valve / passages

Faulty camshaft position sensor

Defective computer

I would start things out with a tune up, new plugs and wires, wires break down after time and could be grounding out, or arcing between themselves causing a misfire.

Replaced the MAF sensor - nothing. Took it to a authorized toyota shop & checked compression which check out good and put the computer on. Computer read mis-fire on cylinder 1, and then multiple misfire (like it would jump around). We went ahead and replaced the fuel injector on cylnder 1 - did not solve problem as when we hook the computer up, misfire seemed tp stay at idle and seem better when running high RMP, but check engine light is on as it never went away. Went ahead and replaced the coil pack to cylinder 1 - nothing. what am i missing?

P0300 Diagnostic Code - Random/Multiple Cylinder Misfire Detected

Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.

A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

Symptoms may include:
* the engine may be harder to start
* the engine may stumble / stumble, and/or hesitate
* other symptoms may also be present

Causes: A code P0300 may mean that one or more of the following has happened:
* Faulty spark plugs or wires
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector(s)
* Burned exhaust valve
* Faulty catalytic converter(s)
* Stuck/blocked EGR valve / passages
* Faulty camshaft position sensor
* Defective computer

Possible Solutions:
- If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
- If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.


Hope helps, and keep us updated.

Sometimes you can use digital multimeter to check for ignition mis-fire.
With engine idling, touch spark plug wires, where applicable, one at a time and note the reading. You don't take the spark plug wire loose and you don't penetrate the insulation, just touch it. Some of the readings I've seen around .6 or .7 volts, not even a full volt. If you find one or two that are bouncing off zero, then you backtrack those. It's an inductive reading or whatever you want to call it.
Hopefully the misfire code will tell you which cylinder, then you check fuel--spark--compression on that cylinder. If p0300 mis-fire code, multiple cylinder misfires and the system can't determine which cylinder.
You might have a vacuum leak?
The basic for a rough idle, you check for a leak of some kind, fuel--egr--vacuum.

You will need to find out where you are misfiring from IE cylinder 1 -4 or cylinder 1-6 depending on size of motor. With your vehicle you have coils that attach to the spark plug and make the car fire. So you are going to need to replace the coils. Ifyour check engine light is on, and you have or can get a code reader it will tell you where the misfire is. Then you just go to your local parts store and get a new one.

Code P1399 is specific to Honda - it is an error code for "multiple variable misfires detected". P0301-P0304 are common OBDC codes for all cars, specifically "misfire in cylinder X".

You will get the P0301-P0304 codes on your OBDC reader when you plug it in (if actually errors), but will only find the P1399 if you select Honda as the manufacturer.

Just got these errors today on my CRV 2000. Now I have to figure out what is causing two of the cylinders to misfire.

When a cylinder mis-fires there is a reason. The dealer should have told you that. Most likely you have a fouled out spark plug. Which means you need new spark plugs and maybe wires. All this would be covered in a standard tune up. Once the bad spark plug is replaced, the computer will quit registering a mis-fire. Please give good ratings, they meen a lot to us.... Thank you

have you changed oxygen sensors? also check wire and plug on #2 I changed plugs once and got multiple missfires changed 3 plugs to a different brand and it solved the problem