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Check Engine Light On And Idle High Can Someone Help

Discussion in 'General Tech and Maintenance' started by tp17svt, Sep 3, 2007.

  1. tp17svt

    tp17svt New Member

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    i just put on a performance aftermarket exhaust header on my 2002 honda civic lx 2door, 4 cylinder to replace the manifold and catalytic convertor. when i put the exhaust header on i only put on ONE oxygen sensor and it was the upper one(before the manifold). Now my check engine light is on and my idle is a little high, i was just wondering if maybe i should put the other oxygen sensor the lower(after manifold) one on and that would fix the problem or do i need a tune up on my car to reprogram the computer. Or is there something else that i need to do that i have not figured out please help.
     
  2. boostin4fun

    boostin4fun Boosted ls/vtec ohh yeah!

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    You are going to have to hook up your other oxygen sensor. Did you eliminate the catalytic converter? Sometimes when you do you will also throw a check engine light code for catalytic converter ineffiecieny because the secondary o2 sensor is not reading much cleaner then the 1st. You might want to run a high flow cat that could possibly avoid that problem if it does happen.
     
  3. tp17svt

    tp17svt New Member

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    i put on the oxygen sensor but the engine light is still on and i dont want to put a catalytic convetor back on it. is there any other possibly way to elimate the engine check light but like a tune up electronically.
     
  4. reikoshea

    reikoshea HS Troll...And Mod Moderator VIP

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    i remember reading about making an emulator for an o2 sensor for people in your exact situation.

    #1 its highly illegal (even in states that dont do emissions testing).
    #2 it requires some knowledge of electrical components.

    Basically what youd be doing is setting up resistors in the right fashion to emulate a 14.7:1 reading on the o2 sensor.

    After thats done youll have to clear the codes, cause it wont clear on its own.

    I dont know why your so against putting the cat (or at least a high flow one) back on the car. Youll lose maybe 3 horsepower by adding it, and you wont have to "hack" your ecu for the car to run right.



    To do the mod i mentioned above basically youll have to splice into the primary O2 sensor wire, then wire in a 10-25ohm 1/2 watt resistor, followed by a 1uf (micro farad) 25 capacitor, and then throw that to the ground on the seconday o2 circuit.

    You might also need a 4-7ohm 50 watt resistor to emulate the heater circuit.

    It sounds easy, but you can easily screw up both sets of wires if you do it wrong.
     
  5. boostin4fun

    boostin4fun Boosted ls/vtec ohh yeah!

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    I dont know why your so against putting the cat (or at least a high flow one) back on the car. Youll lose maybe 3 horsepower by adding it, and you wont have to "hack" your ecu for the car to run right.

    Exactly. Why make things really difficult for yourself for nothing? Your not going to have some huge power gain from removing the cat. Get a high flow one or have your check engine light on and lose more power then the car would normally have from the factory!
     
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