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Discussion Starter · #1 ·
Can't figure out why my 05 STi goes into limp home mode after flooring the pedal. I have scheduled a date with the dealer but thought someone on this forum might have a quick answer. The closest dealer with a scanner is 1.5hrs away;(

Thanks in advance,
Guy
 

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yeah what does "limp mode" mean? How do you know it is doing this? more info......
 

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hmm I've thrown a lot of Cel's going through my mods and never was in "limp mode" guess I missed that CEL... :lol:
 

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RallyPartsExpress.com said:
yes that is correct. If you throw the wrong CEL your car will go into limp mode.
Never had a "Limp Mode" issue when my CEL was on.

Ive seen limp mode on my friends STi and you cant really move LOL.
 

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There are literally 100's of different OBD-II CEL codes. There is even a difference when the CEL blinks rapidly instead of being on solid. Check engine lights are only the result of a problem. You wont know what that problem is until you read the CEL log. If you are goes into limp mode your CEL will be on.
 

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why not just go to your local auto parts store and have them check for a CEL?
 

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RallyPartsExpress.com said:
There are literally 100's of different OBD-II CEL codes. There is even a difference when the CEL blinks rapidly instead of being on solid. Check engine lights are only the result of a problem. You wont know what that problem is until you read the CEL log. If you are goes into limp mode your CEL will be on.
Yes now you corrected yourself by saying when you do go into limp mode, your CEL will be on.

However when you get a CEL, NOT always will the car go into limp mode, since there are literally hundreds of different codes.
 

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Discussion Starter · #14 ·
Sorry to not get back sooner. The only mods at this time (motor on stand waiting for Motec) are an APS intake and a Perrin crank pulley.
I do live on a long dirt road which may be causing the dirty MAF.
The problem happens when I put the gas pedal ALL the way to the floor. When I do this the car's power goes off like a light switch and when I give it gas I get nothing. The check engine light comes on and the cruise light blinks. After stopping and turning the car off several times I can drive away fine but the check engine light and cruise light stay on for about 4 more key turns.
I could drive the 1.5 hours to the dealer as it is still under warranty for the moment but I'm not sure if they'll like the full roll cage. Although, I know the cage has nothing to do with the CEL issue.
Any ideas on which CEL it may be?

Thanks guys for all your input!

Guy
 

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Discussion Starter · #16 ·
It's funny, the only time this has happened was when I floored it (rarely do as I usually roll the throttle) racing a car.
Do you think I felt bad? Sure did.
 

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LightWerkz said:
Yes now you corrected yourself by saying when you do go into limp mode, your CEL will be on.

However when you get a CEL, NOT always will the car go into limp mode, since there are literally hundreds of different codes.
Sorry thats not what i was saying origionally or meant :) It might have sounded like that but you can say it to yourself a few different ways. :) I meant if your car goes into Limp mode you will have a CEL. Specifically if your OBD-II system detects a problem and you throw the right code it will put the car into limp mode. There are a set of specific codes that will do this, not all of them will. Again the code is not the problem but the end result.
 

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Discussion Starter · #18 ·
Going to Autozone in the am. I will let everyone know tomorrow what code comes up.

Thanks,
Guy
 

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Discussion Starter · #20 ·
OK, here's the scoop. Codes puled were P2123 and P2128. Dealer states these are the codes for Accelerator position sensors D high input and Accelerator Position sensor E high input.
Basically when I took out the carpet to weld in the roll cage I took out a rubber stopper that went behind the gas pedal. I'm sure it has something to do with the drive-by wire. Now when I floor it the pedal goes too far for the potentiameter and the car goes into limp mode. Part to fix (as potentameter is not beyond it's limits) is #36010FE020 at $183.

The moral of this story is be careful of that rubber stopper behind the pedal.


Guy
 
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