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  1. #1
    Sr. Apprentice twiggy's Avatar
    Join Date
    May 2009
    Location
    anderson,sc
    Posts
    33

    Default check engine light????

    So every once-in-awhile i get a check engine light, i put my OBD2 scanner on it and it give's me the same code every time- "catalyst effieciantcy below threshold" , I'm not sure what that means.
    Any ideas????
    Attached Thumbnails Attached Thumbnails side view at barn.jpg  
    -Jason
    99' Chevy Tahoe
    5.7 Litre Vortec
    Flowmaster true dual exhaust
    Super sport fog lights
    grille guard
    Pioneer stereo W/ 12"sub
    bike & kayak rack
    stock 03' tahoe wheels
    snow tires

  2. #2

    Cool check engine light???

    Looks like your cat took a dump.

  3. #3

    Default

    Yep, bad cat or bad O2 sensor. You don't state the code number or which bank, when I got that code (P0430), I switched the post cat O2 sensors to see if the code followed the sensor or not. Once I determined it wasn't the sensor, I replaced the cat.
    '98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
    '92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
    "My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World

  4. #4
    Sr. Apprentice twiggy's Avatar
    Join Date
    May 2009
    Location
    anderson,sc
    Posts
    33

    Default

    Honestly, i dont even have a cat, it didnt have them when i bought the truck. could the previous owners wired something wrong when installing the dual exhaust?
    -Jason
    99' Chevy Tahoe
    5.7 Litre Vortec
    Flowmaster true dual exhaust
    Super sport fog lights
    grille guard
    Pioneer stereo W/ 12"sub
    bike & kayak rack
    stock 03' tahoe wheels
    snow tires

  5. #5

    Default

    If there is no cat, that is why the computer is telling you the cat is inefficient. You will have to put cats in to make it go away.
    Gary

    99 K 1500 Suburban
    78 Silverado Big 10 w/factory 454
    00 S-10 Blazer
    1976 Trans Am
    1980 Honda CB900 Custom

  6. #6
    Sr. Apprentice twiggy's Avatar
    Join Date
    May 2009
    Location
    anderson,sc
    Posts
    33

    Default

    well i can erase the codes with my scanner. and after i erase it, the code comes back in about a month. so i'll just keep erasing the code

    Thanks
    -Jason
    -Jason
    99' Chevy Tahoe
    5.7 Litre Vortec
    Flowmaster true dual exhaust
    Super sport fog lights
    grille guard
    Pioneer stereo W/ 12"sub
    bike & kayak rack
    stock 03' tahoe wheels
    snow tires

  7. #7

    Cool check engine light????

    When you clear the code it take a few cycles before it throws the code again. The truck doesnt know if the cat is removed or bad, it just sees dirty O2.

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