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  1. #1

    Default 99 silverado loss of power!

    I have a 99 silverado 4.3l that is having some serious loss of power/bogging/accelerating problems. Ive changed plugs wires cap and rotor air filter fuel filter and even replaced muffler and still have noticed no difference in the way the truck runs. My first thought was bad o2 sensors but the only code that come up on my truck is the EVAP which I was told will not affect the way it runs. If anyone could help me out with this that would be great!

  2. #2

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    Quote Originally Posted by Jlipovsky View Post
    I have a 99 silverado 4.3l that is having some serious loss of power/bogging/accelerating problems. Ive changed plugs wires cap and rotor air filter fuel filter and even replaced muffler and still have noticed no difference in the way the truck runs. My first thought was bad o2 sensors but the only code that come up on my truck is the EVAP which I was told will not affect the way it runs. If anyone could help me out with this that would be great!
    maybe a plugged cat. Pull the o 2 sensor out that's installed in front of the cat and drive it around the block. If it improves, you know the car is more than likely plugged
    Chuckie!!!


  3. #3

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    Forgot to mention I just replaced the driver side cat due to rattling noise and the inside of the cat was completely hollow. But now rattling still seems to be coming from the o2 sensor after the cat which I can't break loose. Also wonder how the cat could be hollow and no code be thrown?

  4. #4
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    Quote Originally Posted by Jlipovsky View Post
    Forgot to mention I just replaced the driver side cat due to rattling noise and the inside of the cat was completely hollow. But now rattling still seems to be coming from the o2 sensor after the cat which I can't break loose. Also wonder how the cat could be hollow and no code be thrown?

    the damaged cat converter with no internal baffles where do you think these metal parts go ...?

    the mufflers do get plugged up when these things occur.. also should the cat converter get destroyed you have to find out why they over heated and melted down. this would be caused by unburned fuel..

    to remove a o2 SENSOR stuck with the pipes hot place a cold wrench on the O2 and loosen.. when the pipe cools finish the removal/replacement.

  5. #5

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    What can I do to improve my trucks towing capacity?

  6. #6

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    My truck does seem to be running rich but one in a while it will kick in and run good my one thought is that baffle from the old cat is lodged down the exhaust resisting flow. Or a have a bad o2 sensor or MAS

  7. #7
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    if the MAF/O2 is bad the DTC check engine light will surely come on. restricted exhaust if not too bad no codes..when it gets bad p0300 is common.

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