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  1. Error codes, P0401 , P0404??

    911 Problems Forum
    My 05 ( with 4" exh, chip, intake ) is throwing P0401 =EGR flow insufficient and P0404= EGR control circuit performance. Do I need to worry about these codes? Will it effect my truck negatively? Can I run with them on?
  2. 03 with codes that I can't fix?

    01-04.5 LB7 Duramax Powertrain
    I have an 03. I live in Ca. and I have to smog my truck this month, and it won't pass because I have a cel on I have cleared the codes, and replaced parts for the codes but light keeps coming back on any sugestions the codes are P0101, AND P0404. I have replace the MAF sensor, a new EGR valve. I...
  3. p0101 and knocking

    911 Problems Forum
    Not really sure if this is urgent but...\P Put on an S&B drop in filter about a week ago and today I started getting a nasty knocking sound and pulled a p0101 code for the Mass Air Circuit? Any suggestions? Do I need to pull the S&B and clean the MAS? Is cleaning it possible without damage...