09 cobalt bogs down, stalls, bad fuel economy

Discussion in 'LS, LT, LTZ' started by al3xjc, Feb 18, 2020.

  1. al3xjc

    al3xjc Junior Member

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    I have an 09 cobalt LS, my car is throwing P3000 (CAN data bus, instrumentation - glow plug warning), P0401 (Exhaust Gas recirculation flow insufficient), and a P0128 (Coolant Thermostat, temp below regulating temp) Just repaired a very cracked flex pipe and o2 sensors. When "cold" started it will sometimes stall out, if I clear the codes the RPM's will bounce from 900 down then back up a few times and catch itself but will sometimes just stall out instead of catching itself. I also use to get 30 MPG now get 18! ANY help or ideas is appreciated! Thanks!
     
  2. 1/4 million

    1/4 million Junior Member

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    Have you cleaned the Throttle Body. its at least an easy maintenance item you can try
     
  3. BGreen

    BGreen Junior Member

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    Stuck open EGR valve? I've been told if it stuck open it could cause bad idle and mpg drops.
     

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