Rep Power: 0

Ok so I'm not dumb and I do know why my check engine light is on and all that, but I'm not sure if I'm being told the truth about it. I replaced the factory header on my 2001 Civic Lx and obviously when doing this it took the cat out since it's built into the header itself. So of course my check engine light is on and all that bull. Well I was talking to a guy today who has worked on my exhaust for me before and he was telling me that there is no way to get the light off because even if I put a high performance cat on the o2 sensors won't read it so therefore it would be a waste of money not to mention my light still won't come off. So obviously my question is wtf? I know there has to be a way to get that light off without puttin the damn factory header back on. Not to mention he was telling me since the light is on its actually hurting my performance so is that true? I tried looking through here and didn't really see anything like this in here so I just figure someone could help me out

 
Rep Power: 261

theres an O2 sensor in the header, which is throwing an upstream O2 sensor code (well, only O2 sensor anyways).

 
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yeai know that cause i put the header on myself so i saw. my question is how do i fix it so i dont have that light on anymore

 
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move the sensors down and put in a cat. High Flow cat WILL get rid of the CEL, if the sensors are installed in the right location. There are probably 2 O2 sensors on your model of civic, the first one should be right in front of the high flow cat, the second, about 3-4 inches behind the cat. Whatever the guy told you about the highflow not clearing the code, it will. Guaranteed.

 
Rep Power: 0

Ok so I saw a thread where someone was told to use a spark plug non-fouler and put them in front of the o2 sensor and somehow it's suppose to trick the ecu i guess into thinking everything is fine. Does this work? Cause honestly I would rather find a way around getting a high flow cat and just rigging up a little modified way of getting the CEL off. Any help I would definitely appreciate it

 
Rep Power: 389

Yes, it basically moves the head of the sensor out of the pipe a bit so its not reading as much pollutants in your exhaust. You can go to autozone and barrow a obd2 code reader and see which one is throwing the code. There more info in my exhaust FAQ link in sig. AND yes, its hurting your performance and fuel economy- the sensors are there to feed info to the ECU- the ecu doesnt know if it should dump fuel, restrict flow- it has no idea because its getting a bunch of info thats outside of the parameters it can accept. Fix it, then clear the codes and your engine light will be off.

 
Rep Power: 812

isnt only the primary sensor used to calculate A/F ratios, and the second only for emissions?

 
Rep Power: 246

yes the first one is to run the engine at stochometric and the second one is so the ECU and check that the catolitic converter is working as it should.

 
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So I need the 18mm ones right? and then i think its like use a 1/2 inch drill bit on one of them? Oh and I only need to do this to the bottom one correct? I know its a lot of questions but I'm definitely trying to make sure I do everything right so I don't screw it up more you know?