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  1. #1

    Default 2003 silverado check engine light

    I have a 2003 silverado with the 4.8l gas engine. A couple of weeks ago the check engine light came on so i used a code reader and it was saying the truck was running too lean. I assumed it was bad gas, once i ran it out though, the problem continued. Now i have read it again and its saying there is a problem with the mass airflow sensor performance, running too lean on bank 1 and 2, and multiple random cylinder misfires. The only syptoms i have noticed is erratic idle. It will go down to 200 or so then back up to 6. So far i have replaced plugs, wires, fuel filter, and mass airflow sensor. Any help with what the problem is would be much appreciated.

  2. #2
    Jr. Mechanic
    Join Date
    Oct 2009
    Location
    Bristol, Rhode Island, United States
    Posts
    104

    Default

    if it's po420 the code was told cats are bad, and at the same time the lean code bank 1 or something like that maybe fuel pump losing pressure... thats all I can help you with... I'm chasing a check engine light that keeps changing codes and these are the 2 most frequent.....

  3. #3

    Default

    Alright thanks. plan to have it checked out tomorrow so ill update details

    Cody
    Grand Prairie, TX
    2003 Silverado LS
    4.8 V8
    Helix Power Tower Throttle Body Spacer
    Cherrybomb Extreme single 3 in/dual 2.5 out dumped
    8000k HIDs
    3.73 gears
    BFG Long Trail T/A's

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