[blaznlow]

I recently purchased a SI mid last year. never once had a problem untill recently I got a CELl. I got the code checked and its p0420. The car has a race header installed. I purchased a Ebay defouler and the CEL came back 1 day later. funny thing is when the defouler was installed the code was for the sensor itself. I replaced the secondary O2 Friday and had no issue untill the CEL came back on tonight. the sensor is currently installed without the defouler i will try putting that on tomorrow after work. I figured I would ask you guys to get any helpful input. I have searched for this issue numerous times but it seems like every issue is slightly different.

Any help is greatly appreciated!

Thanks.

 

[DwnSft7FijiSi]

This is normal when you install a header and eliminate the cat. Defoulers are supposed to trick the sensors but they are not always effective.

There are also different types of defoulers, don't know what you have, so depending on the design or spacing of yours, it could be that the distance from the main pipe to the o2 sensor is still not far enough to consistently filter the amount of gas that reaches the sensor.

Performance wise, it will not affect you in anyway or cause any damages. The only con is that the cel will be lit up on your dash.

 

[blaznlow]

this is what i go off ebay O2 oxygen sensor angled 90 degree 18mm test pipe extension M18 X 1.5 | eBay

i understand. the original owner had the header on for 15k with no issues so im just wondering why its on now all of the sudden. its a vibrant header BTW. which defouler would work best?

 

[DwnSft7FijiSi]

Don't mean to hate but you got a cheap crappy one. Vibrant actually made a defouler that matches to their header. If the ebay one is the only one you are using, the problem is that it lacks in filtering power and spacing. I have one exactly like the ebay one and it sucks bad.

The owner before could have had done something to eliminate the cel but because I don't know the conditions in which he originally had it I can't really say for sure what happened during the transition to you.

 

[blaznlow]

Lol. I wouldnt consider that hating at all. i will purchase the vibrant one and hopefully it will eliminate the annoying light.

 

[DwnSft7FijiSi]

Another option I will suggest, if you have the funds, is to buy flashpro. You can disable the second o2 sensor's function and eliminate the cel forever. Defoulers are really just gambles. It works sometimes and it doesn't at times. So long as the sensor is still working and gases hit it, too much or too little, it will trigger a cel.

 

[blaznlow]

i will also consider that option as well.