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  1. #1

    Default Cleaned throttle body idle issue.

    Cleaned my throttle body on my 2008 silverado 5.3l and idling a little off. Seems to be too high, anyone know should I take to dealer to recalibrate or is there another option? I decided to clean after check engine came on and code p0121 was reading on diagnostics.

  2. #2
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    Enkeiavalanche's Avatar
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    Sounds like a Job for Seafoam...
    08 Z71 Avalanche Mods to date: K&N CAI,Hellwig Swaybars and End Links, Corsa Sport Exhaust, Superchips Programer,IPCW LOF & 3rd brake light and tails, AMI Gas door,Show Hooks and Door locks, Enkei Wheels, with Pirelli tires, StreetScene Bowties, Grant Steering wheel,Muth signal mirrors,SSBC Big Brake kit,Huskyliner Mug gards,Floor mats and Hood shield, McGard Lug nuts and locks, Bedrug, Cervini's Ram Air hood,35watt HID Fog lights, Sylvania bulbs all around ZXE's Highs and Lows, WhiteNight Back up lights,Sirius and HD Radio, SnugTop sitting on deck now Got a Softopper on now,Tempress Boat Hatches.... New Bilstein shocks are on... New Mods coming soon..... X

  3. #3
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    Default

    what product did you use to clean ? high idle would indicate a air leak/vac leak.

    the 121 means the MAP and the TPS are out of wack. not within the programed operation. usually a leak.

  4. #4

    Default

    Cleaned my throttle body on my 2008 silverado 5.3l and idling a little off. Seems to be too high, anyone know should I take to dealer to recalibrate or is there another option? I decided to clean after check engine came on and code p0121 was reading on diagnostics.
    This is a problem we always had with the computer-controlled throttle bodies on these new trucks when I was doing my work study at my local GM dealer. As the gunk builds up inside the throttle body, the computer slowly adjusts the idle position of the throttle body to account for it and regulate the air flow at idle. The problem is, when you clean the throttle body and the gunk is suddenly gone, the computer thinks that the sudden change is an incorrect reading and doesn't compensate for that. We would always have to use the Tech 2 to reset the throttle body position whenever we cleaned a throttle body. You could try driving it long enough to adjust itself back, or disconnecting the battery for long enough for the computer to drain all of its residual power and reset, but neither of those is guaranteed to reset the throttle body position.

    The only way that I know 100% works is to use the Tech 2 to do a relearn of the throttle body position sensor so that the computer will put the throttle body back at its normal idle position.

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  5. #5
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    This why I like the pre 98 vehicles, TPS can be reset by holding the gas pedal 3/4 way down and starting the vehicle and letting off the gas and shutting the vehicle off. BAM!! Tps reset lol!!!

    Good luck with your issue!!

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