Check Engine Light...

Discussion in 'Modifications And Maintenance' started by BrinkSTi, Aug 10, 2010.

  1. BrinkSTi
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    BrinkSTi Well-Known Member

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    I have a 2006 STi with 40,600 miles on it and i was driving on the highway when the check engine light came on. My car has full turboback, cai, and i just recently got it retuned with the grimmspeed boost controller. The car runs and drives fine. Does anyone have an idea of what this could be? Thanks
     
  2. StatGSR
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    StatGSR Well-Known Member

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    No, not until you pull the code
     
  3. Bullwinkle
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    Bullwinkle Well-Known Member

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    Sent you a return to your PM. Get the CEL checked and post the number.
     
  4. JasonoJordan
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    JasonoJordan Well-Known Member

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    my guess is u have tiny unicorns in ur exhaust poking holes in it and ****ting in your filters...come on man just go to the local parts store borrow the code reader read the codes write them down and google them. done
     
  5. BrinkSTi
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    BrinkSTi Well-Known Member

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    I didnt know parts stores could do it. Morries wanted 100 bucks and i wasn't about to pay that. But ill get it checked out and post the code.
     
  6. BrinkSTi
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    BrinkSTi Well-Known Member

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    PO420 is the code. It suggests that it could either be rich A/F ratio, ignition system malfunction, or a faulty catalytic converter. The car runs fine, any idea what the problem could be? Thanks
     
  7. SurlyOldManMN
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    SurlyOldManMN Omdat fok jou

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    I'd go to my tuner and ask them about it. Possible A/F ratio issues immediately after a tune should warrant a follow up question or two. I'm no tuner (VERY far from it), but had I just purchased the service that would be my first stop for possible insight.
     
  8. Bullwinkle
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    Bullwinkle Well-Known Member

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    Yup, P0420 is one that should've been deleted. I must've used your stage 1 map as a base for your current map, PM'd.
     
  9. readymix
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    readymix ...Lest ye be trod upon... Staff Member

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    Yup, just a follow up here. Anyone with a custom tune via OpenECU or the like, your tuner should normally disable P0420. P0420 is cat inefficiency, which usually results from removing the catalytic converters from your car (i.e. installing a turboback exhaust). The resulting readings from your rear O2 sensor will piss your ECU off and throw that code. Normally, your tuner simply disables that code in your tune so it doesn't show up, and it's usually a quick fix for the tuner to simply go in and suppress it. If you have bolt on exhaust bits, and no tune, this will likely pop up within 1000 miles of installing those parts. Your best bet is to get a custom tune. Or you can keep clearing the code by pulling the negative terminal from your battery then pumping your brake pedal a few times and re-connecting the battery terminal.
     
  10. pillboy
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    pillboy Well-Known Member

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    If it pisses off the ECU, I wonder what removing the cats does to the Feds?
     
  11. 03subyR
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    03subyR Well-Known Member

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    I had that code with my catted Invidia DP. So I disabled it.
     
  12. readymix
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    readymix ...Lest ye be trod upon... Staff Member

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    Not sure, but when the local police saw me in my driveway bashing the catalyst out of my CC with a galvanized pipe and a hammer, they just gave a wink and a nod and drove on.