Misfire on all 4cy obd p1399 - 1998 Honda Accord

The OBD-II error code P1399 and P0141 for a Honda CRV 1999 are as follows:
P1399 - This code indicates that there is a problem with the misfire detection system in the vehicle. This code is often accompanied by other codes that indicate which specific cylinder is misfiring. Causes of this code could include a faulty ignition system, a clogged fuel injector, or a problem with the engine control module (ECM).
P0141 - This code indicates a malfunction in the oxygen sensor located on Bank 1, Sensor 2. This sensor measures the oxygen content in the exhaust gas after it has passed through the catalytic converter. Causes of this code could include a faulty sensor, a damaged sensor wiring harness, or a problem with the vehicle's computer.
It is recommended that you have a certified mechanic diagnose and repair these issues to ensure proper operation of your vehicle.

Tech notes
Adjusting the valves will usually fix this problem.
When is the code detected?
The control module monitors the crankshaft speed and has detected a misfire condition
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/loss of power
- Hard start
- Engine hesitation
P1399 Honda Description
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.
- Valve clearance out of range

PO300 and P1399 are random cylinder misfire detected.
PO301 cylinder 1 misfire
PO302 cylinder 2 misfire
PO304 cylinder 4 misfire
PO306 cylinder 6 misfire
I would say that you have damage to the ignition wiring harness or you ECM is failing.

P1399 is a random engine misfire.

right off all data

p1399 is a random misfire code and honda has reported for various models that this could be caused by clogged egr ports, in addition there is the possibility that the valve clearance spec may be out of range.check plugs and wires first and proper gap.

All these codes indicate you have a misfire on cylinder number 5.
P1399/P0300 - Random/Multiple Cylinder Misfire Detected
P0305 - Cylinder #5 Misfire Detected

Causes:
- Improper spark plug at cylinder #5
- Insufficient compression at cylinder #5
- Incorrect fuel pressure
- The injector circuit is open or shorted at cylinder #5
- Fuel injector #5 may be faulty
- Intake air leak at cylinder head

Solutions:
- Perform Injector Service
- Replace Spark Plug #5
- Replace Injector #5
- Replace Ignition Coil #5

P1399- Manufactures control Ignition system OR Misfire

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires; the EGR valve to make sure it doesn't leak; your fuel pressure which can cause random misfires if the pressure is too low; and injectors if they are really dirty. If you have really high mileage, I probably would first just change out the plug wires with a new set, then reset the DTC and see if the code comes back.

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.

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires (as mrgreenz suggests); the EGR valve to make sure it doesn't leak; your fuel pressure which can cause random misfires if the pressure is too low; and injectors if they are really dirty. If you have really high mileage, I probably would first just change out the plug wires with a new set, then reset the DTC and see if the code comes back.
Hope this is helpful as well.

P1399- Acura = Random/Multiple Cylinder Misfire Detected

Acura forums state that It could be a coil pack or O2 sensor, or EGR.