Results 1 to 2 of 2

Thread: Years Later Cos Quits?

  1. #1
    Member
    Join Date
    Oct 2011
    Posts
    95

    Default Years Later Cos Quits?

    Hey guys,
    My truck has had roughly the same tune in it for years and years, a COS with extra fuel in boost and semi open loop. Lately I noticed it was down on power and the WBO2 didnt move much at idle. Scanned it, no semi open loop, only open loop, and when it hits boost it does not command or deliver a richer mixture.

    What could change? O2s are reading what seems to be normal data, nothing was changed in the software for years. Only thing is the battery disconnected, did the COS get wiped out?

    I'm just getting started with this one but I'm not even really sure what would change so maybe some of you older guys may have seen something? Thank you!

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    COS does not get wiped out.

    Do you get any DTC's...?

    What is rail pressure...? Do you have a manifold-referenced FPR...? Had fuel filter been replaced...?

    Are you running MAF...? Is it clean...?

    Is WB working ok...? Is it indicating rich or lean...?

    I have more questions...

Similar Threads

  1. 2005 ssr speedo quits when tires spin
    By Wichita Dyno in forum Gen IV V8 Specific
    Replies: 0
    Last Post: July 24th, 2014, 06:42 AM
  2. What Years for Which ECM
    By Ninety8C5 in forum Lounge
    Replies: 1
    Last Post: October 9th, 2009, 02:51 PM
  3. ITs been YEARS
    By ssdungeon in forum Gen III V8 Specific
    Replies: 1
    Last Post: September 9th, 2009, 07:37 AM
  4. The next 5 years
    By ZL1Killa in forum General (Petrol, Gas, Ethanol)
    Replies: 17
    Last Post: February 6th, 2009, 09:25 AM
  5. Diffrences through the years
    By cmitchell17 in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 4
    Last Post: November 10th, 2007, 09:26 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •