Momentary power loss at 4200 rpm
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This is a discussion on Momentary power loss at 4200 rpm within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; Hello all, new WRX owner here. I have a 2012 four door with 17k miles. To he best of my ...

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    Momentary power loss at 4200 rpm

    Hello all, new WRX owner here. I have a 2012 four door with 17k miles. To he best of my knowledge, the only mod is a Cobb intake. I have noticed in 2nd and 3rd gear when I am heavy on the gas pedal, the car will momentarily lose a bit of power at 4.2krpm and then it comes right back at about 4.8krpm and above.

    I have never owned a turbo before, but I suspect the problem is in the turbo system somewhere. Or it may be completely normal for all I know. I would love some input from some of you experienced users before I take it in for service. Thanks!

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    Registered User Ampliified's Avatar
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    You have an intake but no Accessport? If so I would go take off that intake and or buy yourself an access port.
    2012 DGM WRX - Stage Two 93 - Stink Eye Mob #908
    The Epic Life of Emily the WRX

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    I would love to tune it, but I am afraid of having warranty claims denied. The previous owner put the Cobb airbox on, but left the stock one in the trunk. Do you think switching back will solve the power loss problem?

  5. #4
    Registered User jeremydingeman's Avatar
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    Try swapping the Cobb for the factory box. It might be a free fix for you.
    Find a low-mileage one-owner unmodified '04/'05 and you're golden.

    Understeer is when you hit the wall with the front of the car.
    Oversteer is when you hit the wall with the rear of the car.
    Horsepower is how fast you hit the wall.
    Torque is how far you take the wall with you.

  6. #5
    MAINEiac 11blackSTi's Avatar
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    If you leave the cobb intake on with no tune you are more likely to have a warranty issue than if you do tune. You're stock tune is not designed to work with that intake. I would recommend taking it off. Not sure on your power hesitation issue. The stock tune is known to not be smooth so it could be completely "normal."

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    Master Baiter EJ257's Avatar
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    Massive correction to the MAF scale is needed for the Cobb intake. I would assume the "power loss" you're describing is the car pulling timing due to knock, both from the factory tune, and the addition of the Cobb intake. I don't have a map handy to give you specific details, but it's significant.

    Either reflash the ECU to account for the intake or put the stock airbox on.
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

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  8. #7
    Registered User wrxnguyen's Avatar
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    If you do take off the cobb airbox and go back to stock I'll take it for u

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    Ok, I will swap them out ASAP.

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