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  1. #1

    Default reduced engine power

    wondering if anyone can give advice.

    Bought 2005 suburban with 38K miles on it about 6 months ago.

    After 2 months check engine light and reduced engine power went on.

    Took it to the local dealer in Norfolk Va.
    Codes showed throttle body issue and part replaced.
    2 weeks later same issue, took back in and had the "wiring" replaced per senior GM tech advisor.

    Ran fine until over the weekend when I was towing my boat across the cheasepeake bay bridge with the ac on and it powered down to max of 10mph in the first tunnel....lots of fun...Turned engine off and restarted it and it ran ok for about 30minutes with ac on and same thing. May be coincidental but once i turned the ac was turned off it did not happen again, but i was turned around by that point and was close to home. CK engine light off and reduced engine power off this am.

    Fuel to the flame......Turns out when the truck was under warranty from prior owner and the throttle had already been replaced about 10K before i bought it....although i did not see record of this on car fax!

    Any rec's on what the real problem may be?
    Last edited by millerahf; 06-01-2009 at 01:17 PM. Reason: new info

  2. #2


    The catylitic converter may be stopped up. Or you could have a vacume line on wrong or off.
    08 silverado
    K&N cai
    single in dual out cherry bomb pro
    leveling kit
    custom painted bow ties
    Bed liner
    Tinted windows
    20inch Cruser Alloy Switchblades
    Goodyear Eagle GT2 285/50/20
    1 truly heavy foot + Wait4meperformance SCT Handheld
    100 shot of Nitrous Dyno tune system
    SS front bumper
    Matching painted front grill and bow ties

  3. #3


    I'm thinking it may be a MAF problem. I've heard of power issues due to a problem with the mass airflow sensor. That may have caused the code for throttle body issue. I still consider myself a novice on EFI engines though so it's just a thought. I'm probably way off but it may be something to look into. Are there any other symptoms that you notice? Noises, smells, etc...?


    The fool learns not from the wise man, but the wise man from the fool.

    2004 Silverado 4x4 (Suzie)
    6" Fabtech Suspension Lift
    35" NITTO Terra Grapplers
    18" MB Wheels Predators
    Thrush Turbo Series Mufflers
    on true dual exhaust
    Grille by Option Racing

    1952 3600
    Finally getting torn down to the frame.

  4. #4


    thanks for the insight....spoke to dealer yesterday and they said "more wiring needs to be replaced"....which sounds to me like they are not sure what is really going on with the response to the early suggestions....there has been no abnormal noises or smells and the truck runs fine btwn these recurring episodes.....i appreciate the suggestions.....better ideas then the "pro's" have offered.

  5. #5


    A throttle body will not cause intermittent problems like that. You have an electrical problem. What code set the second time it screwed up?

    2004 SILVERADO 2500HD LS
    Pro Comp Leveling Kit
    285-75-16 Cooper ST All Terrains
    Pro Comp Programmer
    Bilstein Shocks
    Linux Bed Liner
    Tinted Windows

    Other rides:

    1967 Landcruiser <350 Chevy>
    1970 Camaro
    1990 Geo Metro Convertible
    2007 FJ Cruiser

  6. #6


    will check the codes when i pick it up and let the group now...again thanks.

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