2009 Silverado 4.8L V8:  Replace Throttle Position Sensor or Entire Throttle Body?

My Silverado has 130k and is accelerating slowly and drives with less power than normal.  Sometimes if you accelerate too quickly the RPMs shoot up but the truck does not increase speed, followed by the smell of gas.......

Does this seems to be a TPS or Throttle Body issue.  The Throttle Body is much more expensive to replace than the TPS


No check engine light is on

5 Answers

  • 1 month ago
    Favorite Answer

    Its hard to say Dwayne... Your truck is at that magic time in its life when little things start going bad. If it were mine, I'd give it a good once over. Fuel filter, air filter, tranny fluid and filter, spark plugs, EGR valve, serpentine belt, hoses, and new anti-freeze. Give the Mass Air sensor a shot of cleaner, and dump a can of Sea Foam in the fuel tank too. With a dirty throttle body, you  can pull the ducting off between the air cleaner and the throttle body and put it back together with the little red plastic straw on a can of cleaner stuck in one of the joints. Fire the truck up, and keep squirting the cleaner until the truck almost dies, stop, and do it again until the can is empty. Hopefully doing these things will clear up your problem. Its time to do them anyway, and will eliminate a few of the possibilities. Good luck.

  • 1 month ago

    Dude you had better stop trying to play mechanic. The throttle body had nothing to do with your problem! When you have less power then normal or can't get the speed of the vehicle over 40 mph you need to check the exhaust system back pressure. However...if the rpms go up and the vehicle speed doesn't increase the transmission is slipping so start saving for a rebuilt tranny.

  • Anonymous
    1 month ago

    Try removing and cleaning the throttle body first as see if it's any better. Also watch some videos about throttle body injector spray patterns. A dripping injector that isn't spraying right can cause poor acceleration and they're not terribly expensive to replkace.

    Quote: "Sometimes if you accelerate too quickly..."


    We don't drive your truck, so why are you saying you? The proper phrasing should be "Sometimes if I accelerate too quickly". Got that? good. The "you" thing is a bad linguistic habit.

  • 1 month ago

    If the revs are "shooting up", the throttle system is working.

    Engine revs increasing rapidly without corresponding acceleration indicates a transmission problem or slipping clutch.

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  • 1 month ago

    An OBD2 code scanner won't guess. It will give you trouble codes that tell what you need to fix. Pull the trouble codes.

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