Menu

2003 Century random rough idle/misfire at idle

Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › 2003 Century random rough idle/misfire at idle

  • Creator
    Topic
  • April 21, 2013 at 7:35 pm #514489
    BrandonBrandon
    Participant

      Hello All!

      I was wondering if I could get some help with my car a 2003 Buick Century, that currently has me scratching my head, and possibly over-thinking the issue at hand. My car currently has 182k Miles, and the preventive maintenance history is very poor. (the only fluid change it has ever had has been oil changes)

      For sometime now the car has had a check engine light, codes are p0404, p0401, and p1404, but there was no drive-ability issues.

      However as of late, they car has had a intermittent rough idle/misfire at idle. It also is giving off a strong exhaust smell during the rough idle/misfire, and is getting terrible gas mileage. However at acceleration it still has plenty of power, and no hesitation.

      I have bought a new EGR valve that I have not put on yet, because the EGR in the car is less than a year old, along with a catalytic converter that is less than a year old.

      I already cleaned the intake port for the EGR which was clogged with carbon build up, but now is as clean as could be and installed new gasket for the EGR, but I still have the same issue, maybe slightly worse that it was when it was dirty.

      Any help is appreciated this has really got me scratching my head, and I am trying to avoid throwing expensive parts at it like a EGR if i don’t have to.

    • Creator
      Topic
    Viewing 6 replies - 1 through 6 (of 6 total)
    • Author
      Replies
    • April 22, 2013 at 1:17 am #514517
      college mancollege man
      Moderator

        here is a link to troubleshoot the p0401,p0404

        http://easyautodiagnostics.com/gm_egr_diagnostic/egr_valve_test_1.php

        here is a link to help with the p1404

        http://www.justanswer.com/buick/6gv65-buick-century-custom-2001-buick-century-custom-showing.html

        April 22, 2013 at 2:40 am #514529
        BrandonBrandon
        Participant

          Hello college man,

          Thanks for the reply!

          Ill be honest, I have seen the troubleshooting the p0401 and p0404 page.

          I have not tried these methods since i do not have a multimeter..

          I wouldn’t mind buying a multimeter, its the piercing probes that seems overly expensive(for decent ones).. is there anyway to work around these probes without cutting or stripping the wires?

          Thanks again!

          April 23, 2013 at 1:54 am #514750
          college mancollege man
          Moderator

            check out this link. if you have small sewing pins or sewing needles
            that will work to

            http://www.enduringautomotive.com/how-to-back-probe-a-sensor/

            April 25, 2013 at 5:13 am #515076
            BrandonBrandon
            Participant

              Thanks again college man, that is awesome, now i will not need to buy expensive probes!

              I think i have decided on two multimeters and need help deciding which one would be best for automotive use.

              I am looking at;

              and

              http://www.radioshack.com/product/index.jsp?productId=12988573

              (the radioshack one is 29.99 in my local store, its “Last years model” but from what i can see the one on the link has essentially the same features.)

              If you have other suggestions let me know too!

              Thanks again for your help!

              April 26, 2013 at 6:10 am #515337
              BrandonBrandon
              Participant

                Hi,

                I just wanted to follow up, and also thank you!

                I ended up buying a multimeter and testing the EGR with the paperclip method, Turns out after it was all said and done, the EGR was stuck open.

                I have replaced the EGR and a new gasket, had the codes cleared, took it for a ride, and it idles as smooth as butter now. (Of all the things in my life i have over-thunk, this is the worst one)

                Now my first major issue with the car is fixed! on to the others!

                April 26, 2013 at 9:29 pm #515429
                college mancollege man
                Moderator

                  glad to hear it all worked out.Thanks for the update. 🙂

                • Author
                  Replies
                Viewing 6 replies - 1 through 6 (of 6 total)
                • You must be logged in to reply to this topic.
                Loading…