Cobb stg 2 - rough idle

Discussion in 'Modifications & DIY how-to' started by jay92x, May 5, 2009.

  1. jay92x

    jay92x New Member

    Has anybody had a problem with a rough idle after going cobb stg2?

    I am using the cobb stg2 93oct base and realtime maps. It seems at least once per trip I'll be stopped at a light in nuetral and the idle will jump down, causing the car to shake like I need to give it some gas. My engine hasn't cut off yet. Other times it just sits and idles fine, I haven't really figured out what is different when it happens. I also noticed hat I have to give a bit more gas on launch then I did before.
     
  2. goixiz

    goixiz Active Member

    check and clean MAF
    tune up lately ?
     
  3. 07Ltd#767

    07Ltd#767 The Neighborhood Drunk

    was thinking the same thing
     
  4. monyg85

    monyg85 Member

    I am having the same problem, its not constant but enough to where i noticed something. How would i go about cleaning MAF??
     
  5. FACE

    FACE Active Member

    there is a spray can of cleaner you can get at any autoparts store. Remove maf sensor, spray, let dry, and replace. Very easy my friend. :)
     
  6. jay92x

    jay92x New Member

    Thanks.

    I'll attempt to clean the MAF first. I'll search for a DIY thread so I know how to get to it but it sounds like something even I can do. :) If that doesn't work, I'm near my 60k anyway so I can have that done sooner rather than later and see if that helps.
     
  7. monyg85

    monyg85 Member

    Thanks man, i probably need to get on that too!
     
  8. mokinbird87

    mokinbird87 Active Member

    yup... i dont think it is the cobb because my car has been doing it since the first day i bought it (it is esp. worse with a/c on) and i`ve cleaned my maf sensor + idle control air valve, and either i have done a wacky job or it hasnt solved the problem... the car feels better but the problem is definitely somewhere else for mine. i`m gonna try to fix my stupid leak bet. the downpipe and the midpipe, because i think i am underestimating that leak and how much it can hurt the performance. besides that i have a problem somewhere along the fuel line and a vacuum line (my car smells like raw gas and it definitely smells more than just a catless downpipe). hope you find the problem so i can fix mine haha.
     
  9. SonicBoom

    SonicBoom Active Member

    My car did this from the factory, stage 1 and 2 didn't fix... Protune knocked it out though, doesn't do it anymore.
     
  10. yerrow

    yerrow Active Member

    when the fozzy did it after flashing it was a boost leak.
     
  11. nsvwrx

    nsvwrx Active Member

    Yeah, protune fixed this for me
     
  12. jay92x

    jay92x New Member

    Well I cleaned the MAF last night. Haven't noticed the idle problem yet today, but I will keep a watch on it. For some reason though I feel like my car has lost power. I want to check to make sure I'm getting up to full boost. When I hook up the AP and check live boost, when should I be looking for it to hit the 16psi stg2 target.. 3rd gear at 5500rpm?

    I tried to see last night but I need to strap that AP to my dash so I don't kill myself looking down at it! :)
     
  13. 07Ltd#767

    07Ltd#767 The Neighborhood Drunk

    ^^^

    or get a passenger... :eek:hnoes:
     
  14. jay92x

    jay92x New Member

    ^^^^

    LOL. Yeah, I guess that works too.
     
  15. goixiz

    goixiz Active Member

    clean maf
    refresh ECU please (relearn)
     
  16. b reel

    b reel Active Member

     
  17. jay92x

    jay92x New Member

    Okay my rough idle is gone. YAY! :wiggle:

    I cleaned the MAF and reset the ECU (vishnu reset). However I still feel like I'm missing power I had a few days ago. When I go WOT in 4th gear I see the boost hit 15.0psi. When I go WOT in 3rd I see it peak at 8.0psi ( I need to verify this ).

    Do I just need a tune? Whould an exhaust leak cause something like that?

    I just saw a boost leak thread.. sounds like I might just a lose hose.
     
    Last edited: May 7, 2009
  18. dontcallitarex

    dontcallitarex Active Member

    A boost leak is a possibility but the car often needs to learn the map, especially after a full ECU reset. I know my throttle response was always crap right after doing that for a few hours.

    Also, over the course of the first week with my Stg 2 AP it would only hit 14lbs and then it slowly worked its way up around 16.
     
  19. Batlground

    Batlground Active Member

    It may be something mechanical or it could be something in the ecu. If it is mechanical we can look at it for you or if it is in the ecu we can pro tune it for you.
     

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