What is the meaning of 98 Honda Civic error codes P0300 P0303 P0304? Engine will not start, does not seem to fire.

P0300-p0304 misfire on cylinder 1-4
P1399 random cylinder misfire

po301 to po304 are miss fire codes, 301 cylinder 1, 302 cylinder 2 Etc, p1399 means that this must be a Honda manufactured vehicle. All are misfire codes, Could be plugs, wires, coils. ETC, Check and you will find the problem. God-Bless!

You have done everything except touch on what is wrong . code p0303 refers to cylinder 3 misfire detected===causes ---engine mechanical fault---wiring---ignition/ furl system---injector---RCT/MAF sensor--ECM
code p0304 refers to cylinder 4 --misfire detected===causes -- same as po303
have a compression test done as there are two adjacent cylinders and it may be a head gasket problem

Have you had somebody clear the codes after you installed the parts.If not the codes have to be erased by using a scan tool.

hi!

you need to scan the car to see what code its sorted in your car memory. Go to an auto part store and they will scan it for free and give you the code. Good luck

From www.hondasuv.com:

 

The P1399 random misfire along with one or more of these codes: P0301, P0302, P0303, P0304 -- indicates a problem with the valves. The B20 engines in the 1997-2001 CR-Vs are known to have problems with valves tightening and then 'burning'.

So the first question is when was the last time you adjusted the valves? If you don't know or never have, then have them adjusted. Soon...

http://www.obd-codes.com/

All those codes mean a specific cylinder missfire. Start with tune up. Plugs, wires & air & fuel filters.

A P0304 code means that the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #4.

A code P0304 may mean that one or more of the following has happened:

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

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.

1. P0171: This means that the oxygen sensor has detected a lean air-fuel ratio. This can be caused due to a vaccuum leak or a problem in the HO2S circuit or the HO2S (Heated Oxygen Sensor) itself. (Bank one Sensor one). This is commonly located along the exhaust pipe. It could also be a bad Mass Air Flow sensor or a bad Engine Coolant Temperature sensor. Diagnostic checks will be needed to be carried out to be verified though
2. Well as for the other codes, it means #3&4 cylinders are misfiring. It is a possibility that the P0171 code mite have caused the others to show up. I can be wrong though. But it is a strong possibility. If the air fuel mixtue is too lean indeed, mis-firing will occur, unless it is an actual electronic and not a mechnical problem. By the way, when these codes appear, how is the engine's performance. Does it remain the same or behaves poorly?