» » »

GMC Q&A

Ask Your Question

2002 GMC Envoy Question: Service Engine Light comes On

 

Question

Visitor, Cornelius, NC, April 08, 2010, 07:32

Service Engine Soon light came on, took to Autozone and they ran a diagonistics which said number 3 cylinder misfiring. They told me to put some lucas fuel injection cleaner in it run it and if it didn't work change the spark plugs. The car has over 100,000 miles on it. Added the fuel injection cleaner ran for 2.5 hours and 200 miles. Light was gone, however when I was parking the vehicle it came back on. Next day replaced spark plugs, light out. Ran for 20 minutes light on again. Now what do I check?

2 Answers
Flag This
  • Answer #1

    mastertech6371 April 09, 2010, 20:49
    Profile_thumbnail
     Master

    you have coils that fire the plugs that may need to be replaced. take it to shop for a real diag by a pro, not a salesmann that is not a tech.

    Roy

    Reply
    Flag This
  • Answer #2

    Visitor, December 12, 2010, 06:55

    I had this problem (Mine said 2) I swapped it with 1 and 1 errored, I replaced the coil pack and it worked fine.

    Reply
    Flag This