Results 1 to 6 of 6

Thread: Stinky idle and poor fuel milage

  1. #1
    Potential Tuner
    Join Date
    Jul 2021
    Posts
    5

    Stinky idle and poor fuel milage

    i am not a tuner for the most part just a normal mechanic.
    i have been using hp tuners to change tire size gear ratios trans tuning code and vats deleat on swaped vehicles.
    i have a 2009 silverado 1500 4.8l has tsp stage 3 low lift cam and long tube headers installed.

    i had the truck tuned by a dyno shop that came highly recommended.
    the truck runs real good given its only a 4.8 on 35 inch tires but it smells real rich at idle like makes eyes water rich.
    i was have been watching data and fuel trims are real high at idle and part throttle im not sure if this is normal after tuning i have checked for vacuum leaks and cleaned the maf. also i cant seem to get vcm scanner to do the idle learn
    i bought an afr setup to get more info and make a log file for anyone who is willing to look at it.
    any help would be appriciated.

    the log file posted is without the long term fuel trims turned on that is how i got it back from the dyno shop i have since figured out how to turn them on but need to record a log file to post.
    Attached Files Attached Files

  2. #2
    Senior Tuner
    Join Date
    Mar 2011
    Location
    Ripley, MS
    Posts
    1,865
    It does have some high fuel trims. The first thing to do is a leak check on the exhaust system. Any leaks before the oxygen sensors could cause an issue like yours.

  3. #3
    Potential Tuner
    Join Date
    Jul 2021
    Posts
    5
    Did that smoke tested exhaust no leaks.

  4. #4
    Tuning Addict
    Join Date
    Jan 2015
    Location
    Franklin, NC / Gainesville, Ga
    Posts
    6,813
    Injection timing, O2 settings for the headers and idle spark - fix those 3 and you'll be good to go. You'll also need to retune your air models, but that should be given. You'll never get rid of all of it, but should be a lot better. In fact this tune looks a whole lot like another one on here that had to be fixed a month or so ago. You also have some heater codes for the O2's you need to get fixed or just delete in the cal as they are post O2 codes.
    2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
    2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80

    ~Greg Huggins~
    Remote Tuning Available at gh[email protected]
    Mobile Tuning Available for North Georgia and WNC

  5. #5
    Potential Tuner
    Join Date
    Jul 2021
    Posts
    5
    I got rid of all of the rear o2 codes it was setting no codes come up.

    Thanks for the information I will start researching those 3 things and see if I can get them dialed in.
    I?m sure I will have more questions later

  6. #6
    Potential Tuner
    Join Date
    Jul 2021
    Posts
    5
    these are the log files with the long tearm trims on
    Attached Files Attached Files