GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 5 of 5

Thread: Fuel Cap

  1. #1

    Default Fuel Cap

    DIC keeps displaying "tighten fuel cap" and my CEL keeps having to be reset. Do these caps go bad or is it the fuel neck the cap screws on to? Can't seem to find a definitive answer in here. Trying to re-tighten the cap isn't working.
    2004 Chevy Silverado 1500 w/ext cab and stepside bed.

  2. #2


    Most likely its not the cap its the pain-in-the-as* evap system. I replaced mine and a year later same issues. I just turn the code off when it comes up. I also tried replacing the gas cap which didn't help.

    2005 Chevy Silverado Z71 Crew Cab
    6" Skyjacker lift w/Edlebrock dual front remote resoviour shocks, single rear remote. Rancho skid-plate.
    17" x 9" M/T Classic Lock Wheels, 35" BFG A/T or M/T tires
    4.10 PercisionGears w/factory locker, T/A Performance rear-end cover
    Banks CAI intake, ported throttlebody, JBA coated headers, over-sized Magnaflow cats, Magnaflow cat back exhaust, Diablo tuned
    B&M aluminum deep transmission pan
    Warn brush guard w/Warn 9.5 XP winch, PIAA bulbs, Line-X bedliner, AWS Black tool chest, Extang tonneau cover
    Weather Tech floor mats
    Cover-Craft seat covers
    Dash mat cover
    Formula One window tint
    One black Lab in rear seat.

  3. #3
    Jr. Mechanic BillM's Avatar
    Join Date
    Sep 2010
    Fair Oaks, CA


    SilveradoTrailblazer is probably correct. However, caps do go bad and it is part of the evap system which is smog control stuff. Smog stations check gas caps as part of the smog cert process in Calif. I bet auto parts stores can check your cap for free.
    Bill M. Blown 2003 Tahoe Z71

  4. #4


    As noted the EVAP system has been known to cause this problem and the gaskets on the fuel caps have been known to go bad.
    The fuel cap is the cheapest item so you might want to start there, if that doesnt fix it start looking at any flexible hoses on the EVAP system.

  5. #5

    Default Fuel Cap and CEL

    Thanks folks, I appreciate the ideas. I'll start with the fuel cap even though it physically looks fine. It's a small inconvenience but and inconvenience anyway.

Similar Threads

  1. 02 Yukon SLT 5.3L Flex Fuel, fuel line issue
    By TRyan9441 in forum Chevy Tahoe Forum (GMC Yukon, Cadillac Escalade)
    Replies: 2
    Last: 06-02-2011, 12:19 PM
  2. 2003 Yukon Flex Fuel - Fuel Filter
    By jnt412 in forum General Chevy & GM Tech Questions
    Replies: 5
    Last: 01-06-2009, 10:28 PM
  3. Twitching/vibrating fuel gauge - Not the fuel pump assembly.
    By Springthing in forum Audio, Video & Gadget Tech
    Replies: 3
    Last: 09-26-2008, 05:10 PM
  4. Fuel Gauge sender/fuel pump Together-seperate???
    By TahoeCrowe in forum General Chevy & GM Tech Questions
    Replies: 9
    Last: 09-05-2008, 02:55 PM
  5. Replies: 0
    Last: 11-13-2007, 11:40 AM

Tags for this Thread

Posting Permissions

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