P0304 code
+ Reply to Thread
Results 1 to 11 of 11

This is a discussion on P0304 code within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; I got a P0304 Code on a couple of days ago. I've replace all 4 plugs and the #4 cylinder ...

  1. #1
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15

    P0304 code

    I got a P0304 Code on a couple of days ago. I've replace all 4 plugs and the #4 cylinder coil pack and cleared the code.

    1 day later the car is still misfiring and the same code pop up again.

    Should I replace all 4 coil pack?

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    22,984
    I Support ClubWRX
    No.

    How did the spark plug look from no.4?

    Check the clips and little wire thingies.
    WRX Info Links, Courtesy TheJ
    Man is a brute.... If you're cruel to him, he respects and fears you. If you're kind to him, he plucks your eyes out. Alexis Zorbas
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  4. #3
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15
    The # 4 plug look normal just like the other 3 plugs, I don't get it. No oil or sign of it being lean. Maybe the # 4 injector is clog?

  5. #4
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    22,984
    I Support ClubWRX
    It is possible but not as common as a wiring fault or a coil fault, and you have excluded the latter. Is the car stock? Are there mods that would make it likely the code is legitimate (power mods etc.)?
    WRX Info Links, Courtesy TheJ
    Man is a brute.... If you're cruel to him, he respects and fears you. If you're kind to him, he plucks your eyes out. Alexis Zorbas
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  6. #5
    Moderator Donkey's Avatar
    Join Date
    Apr 2005
    Location
    Da boonies
    Posts
    6,312
    I Support ClubWRX
    Resident Adviser @ WTF Tuning, LLC
    2002 FORESTER S
    1998 FORESTER S




  7. #6
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15
    Car is completely stock. It has 196K miles I've did use injector cleaner. # 4 coil has been replace as well as all 4 plugs. I will double check the wiring.

  8. #7
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15
    Thanks for the link, I will do the following.

  9. #8
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15
    I've just replaced the PVC valve, cleaned the MAF sensor with CRC MAF cleaner and I've also cleaned all 4 of the coil pack plugs. I will pour in a bottle of Sea Foam in the fuel tank and see what will happen next.

    As of now it is still not a smooth.

  10. #9
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15
    I got the same code again today P0304 it is ticking me off. I'm starting to dislike Subaru.

  11. #10
    Registered User fortunesk89's Avatar
    Join Date
    Aug 2007
    Location
    kenosha wi
    Posts
    18
    fuel grade? how fast does it recode? try to ohm the injectors or swap with a different cylinders injector
    2002 plat. silver wrx

  12. #11
    Registered User
    Join Date
    Oct 2010
    Location
    Lowell, MA
    Posts
    15
    I only use premium grade fuel. It recode about every 100 miles. I'm thinking about replacing the # 4 injector. I'll try new inject cleaner for a few more tanks to see how it does. If not I'll replace 1 injector.

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself. We strongly suggest that you stay away from using aol, yahoo, msn, and hotmail accounts. Sometimes the mail server blocks the emails from our server. As a result you will not receive any notifications including the confirmation email.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •