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Cold air inake/ check engine light

Discussion in 'Gen 3 Prius Accessories and Modifications' started by Ragz, Nov 4, 2011.

  1. Ragz

    Ragz Active Member

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    I installed an Injen cold air intake and 2 days later, the check engine light went on. I had it reset at the dealer and next day, again. Am I stuck with this or is there a way to keep it off, other than putting back the original air box?
     
  2. seilerts

    seilerts Battery Curmudgeon

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    You can reset the code by disconnecting the battery negative. No need to visit the dealer. However, I doubt that anyone can help without knowing the code. Must be MAF related? or Lean Burn condition? The two most obvious problems are an air leak downstream of the MAF, or the MAF bulb/air intake temperature sensor is covered in filter oil -- clean with CRC MAF cleaner.
     
  3. Ragz

    Ragz Active Member

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    Just disconnecting the neg will reset? I will try that, and cleaning the maf, thanks
     
  4. spiderman

    spiderman wretched

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    How many miles on the car? Do you notice any improvement with the CAI?
     
  5. Ragz

    Ragz Active Member

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    Almost 18k, Not really anything noticeable
     
  6. revhigh

    revhigh MPG Enthusiast

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    Why did you do it then ???? :)

    Were you 'trying' for some kind of specific improvement ???? Or just messing around ?

    REV
     
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  7. F8L

    F8L Protecting Habitat & AG Lands

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    I would suggest just removing the intake and putting the OEM one back on. The Prius is not starving for air like some vehicles so the improvement in power is negligible or could actually reduce power. I've tried running the OEM intake with the OEM filter at the drag strip then I removed the intake and filter completely to see if it made a difference during back to back runs and I did not observe and improvement. In fact, the biggest variance in ET and trap speed was related to traction battery charge.

    Colder is good for power but not necessarily for fuel efficiency so you could lose mpg with a cold air intake depending on how much it cools the intake charge. I often observe a 5-10deg difference between ambient air temp and intake air temp.

    I'm not against modding a car, obviously, but I don't feel that engine mods are worth the time, money, and stress when it comes to the Prius.
     
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  8. Teakwood

    Teakwood Member

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    Amen to what revhigh and F8L said!!!
    :thumb:
     
  9. adamace1

    adamace1 Senior Member

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    Yea i would just put the oem back on. A cold air intake is just a scam on most cars. If it helped with anything why wouldn't toyota just do it to begin with?
     
  10. Pinto Girl

    Pinto Girl New Member

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    I agree with all of the above.
     
  11. fuzzy1

    fuzzy1 Senior Member

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    ... because cold air intakes (CAI) are intended increase power, not efficiency. That is why they are used by the street racing crowd, not the fuel efficiency crowd.

    In traditional cars with Otto cycle engines, hard core hypermilers want the opposite: a warm air intake (WAI). But where WAI slightly reduces a particular loss mechanism (pumping loss), the Prius' Atkinson cycle engine and its load management do far more to nearly wipe out this loss. So I don't believe there is much potential improvement left for WAI to address.
     
  12. robby3

    robby3 Member

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    A cold air intake makes sense in very hot ambient temps to prevent sucking in the hot air from the engine bay. HKS sells two different intakes, cold air and premium. I have installed the premium kit that replaces the resonated elbow in between the throttle body and the filter box as well as the filter itselfs. No CEL at all.

    Before and after measurments with the Greddy informeter showed an increase of 4hp. Also MPG rose but this may be caused by the increased tire pressure.

    But the drawback is a less smooth kick in of the ICE. Not audible but somehow the power kick in is not that good as it was with the stock parts. The whole intake path has been designed by Toyota to provide an as smooth and as silent as possible ICE start and power handover. This is done with resonance channels and specific air paths. The Injen and HKS Pro removes all of these engineered elements and replaces them with a simple tube and cone filter. Such tubes provide free air flowing but nothing that helps when starting or in low power areas.

    IMHO, the premium suction kit from HKS provided a little more power at the top (5400 rpm) and enhanced the engine bay a little. That's it. An Injen or HKS pro kit makes the engine bay looks much worse and obviously cause problems we not want for a lot of money. Maybe one can see a few hp more power with these but then the car must really be runned at high rpm. Not what a Prous is meant for :)

    Reinstalling the stock parts is recommend for sure but first the error code of the CEL should be read. I bet it is a dirty MAF that should be carefully be cleaned. With such an Injen filter cleanign the MAF is often necessary (had the same issues on Corolla and MR2).
     
  13. volt_killa

    volt_killa volt_killa #ItsATealPrius OPTLMUS

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    just installed the Injen in my 2010 and it was kinda hard to connect the wire harness to the MAF because it of the incorrect orientation of the L-shaped plug... was it the same for you or is it just in my instance?
     
  14. Ragz

    Ragz Active Member

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    Yes it was the same. A little manuvering and it went in, but it was frustrating
     
  15. volt_killa

    volt_killa volt_killa #ItsATealPrius OPTLMUS

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    dang is the sonofagun loud when you push it... so I reconnected the negative terminal and it cleared the CEL, then I went to work the next day. however when I started it up to head home the CEL came on again... guess I should borrow a reader to diagnose it?
     
  16. revhigh

    revhigh MPG Enthusiast

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    I'm guessing that you should come to terms with the fact that you're driving a Prius :D, and that in the case of the Prius ... NOBODY (well ... ALMOST nobody) knows better than Toyota.

    Take it off and throw it away ... or return it if you can ... and learn a lesson from this little experiment !! :D

    Good luck.

    REV
     
  17. cproaudio

    cproaudio Speedlock Overrider

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    Is it really a cold air intake? Is the intake actually routed to the outside of the engine compartment? I see a lot of CAIs where they just block off a section of the engine compartment where the intake is located. It's till sucking hot air from the engine compartment. My 97 Tacoma had factory cold air intake ducts routed through the fender. It's actually drawing air from the outside of the engine compartment.
     
  18. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    The way an Atkinson Cycle engine works, it CAN'T be a cold air intake. 30% of the intake charge has already been in the cylinder at least once and is warmed up.

    The intake valves do not close until the piston is 30% up the intake stroke so 30% of the charge is sucked into the engine then pushed back out into the intake manifold (which is one reason why you should not alter the intake manifold) so the next piston sucks in 70% cold air and 30% ejected air, then ejects 30% of that mix and so on.

    So your attempts to make the intake air cold are doomed.


    (if your intake has less volume that the stock Toyota part, you may be pushing fuel back out of the manifold into the atmosphere, which would be dangerous as it is explosive by design and also mess up the fuel/air ratio as you are 'losing' that fuel. I don't doubt the engine could be 'lean' if the 'cold air' pipe is shorter)
     
  19. Jwb2781

    Jwb2781 Junior Member

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    I have injen short intake, and I like it if only for the sound. But yes, no real gain, and no check engine light on.