How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask sean Your Own Question

sean
sean, Technician
Category: Car
Satisfied Customers: 3104
Experience:  UK based Ford Master Technician. Technician since 1984.
31670004
Type Your Car Question Here...
sean is online now

My emissions warning light has just come on in my 2000 ford

Customer Question

My emissions warning light has just come on in my 2000 ford focus.It flashed at first and now is on permanently. Could you suggest what I need to do to get this sorted?The engine is running sluggishly and jerking slightly also.Many thanks.
Submitted: 2 years ago.
Category: Car
Expert:  sean replied 2 years ago.

Hello, I hope the following assists you.

As the MIL was flashing to start with this would suggest a fault that the engine management has detected may cause damage, the light flashes to alert you to this.

By far the most common fault that causes this is a misfire caused by an ignition system failure, usually the ignition coil, a spark plug or H.T. lead. If a misfire is left then it can cause damage to the catalyst due to unburned fuel.

The poor performance and judder is due to the engine running on 3 cylinders instead of 4.

If possible check the spark plugs, remove them and check the electrodes for signs of burning and the porcelain insulation for any signs of electrical arcing along it. Check the output of the ignition coil, around 75% of the time the misfire is on cylinder 4, if there is no output on cylinder 4 but cylinder 1 is OK then replace the ignition coil, if cylinder 1 and 4 have no output or cylinders 2 and 3 together have no output then check the coil switching circuits.

Start with these points, let me know if you have further questions regarding this and I'll reply as soon as I'm able to.

Best wishes,

Sean.

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Greg

    Greg

    Technician

    Satisfied Customers:

    1067
    Automotive diagnostic tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Technician

    Satisfied Customers:

    1067
    Automotive diagnostic tech
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    4197
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Diagnostic and repair technician

    Satisfied Customers:

    452
    Licensed diagnostic and repair technician
  • http://ww2.justanswer.com/uploads/RO/RobMechanic/068.64x64.JPG Rob's Avatar

    Rob

    ASE Certified Technician

    Satisfied Customers:

    82
    30 years trade experience
  • http://ww2.justanswer.com/uploads/UK/ukiaibal/2012-11-9_205920_SAM0109.64x64.JPG uk_iaibal's Avatar

    uk_iaibal

    UK Car Mechanic

    Satisfied Customers:

    1
    Verified Car Mechanic.
  • http://ww2.justanswer.com/uploads/NA/nabilc/nabilc_avatar.64x64.jpg Billy's Avatar

    Billy

    Trainer/ Master Technician

    Satisfied Customers:

    38
    Trainer 8+ years, master tech. 10+ years, SAE member
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG Mike Kelly's Avatar

    Mike Kelly

    Auto Service Technician

    Satisfied Customers:

    1256
    17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.