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How to bypass the second o2 sensor


cebooh22
03-05-2005, 06:09 PM
Hi im new in the forum... :evillol:

I have an accord with an h22a4 with a little probleme i would like to know how to bypass the 2nd o2 sensor on car.

and would like to know IF you don't do that what can it arrive ....?

And what is the symptom ???


Tx all :icon16:

superbluecivicsi
03-05-2005, 09:25 PM
you cant bypass the o2 sensor, because the ecu needs the readings from the o2 sensor. you can tell the ecu that it is running properly with an o2 sim. the only symtoms you'll get is a CEL and not being able to pass smog.

sivic02
03-06-2005, 02:16 AM
This is the hardest post ever to decipher...if you do have a check engine light, which I am assuming is why you want to bypass it. You can buy an o2 simulator as stated above for 60 bucks or however much those things are. Or you can buy a set of spark plug non foulers for about 4 bucks at an auto parts store, drill out the end of one, put the o2 sensor in it, screw that one into a second non fouler, and screw the two together into the cat. So it goes o2 sensor, drilled out non fouler, regular non fouler, cat. Just pushes the o2 sensor further away from the exhaust flow so it thinks you still have a working cat.

Greenblurr93
03-06-2005, 11:46 PM
www.o2simulator.com (http://www.o2simulator.com)

sivic02
03-07-2005, 12:58 AM
i really dont know why you wanna do that but i think its kindna stupid to bypass the 2nd O2 sensor. Its function is just to monitor the oxygen content down stream or after the cat converter and has nothing to do with the engine performance.

The reason I did this is because I have a test pipe, which gives me a check engine light. Its just annoying riding around with the check engine light always on. Plus if anything DOES go wrong you wont know because the light is always on anyway. But you are right a secondary o2 sensor wont do anything performance wise, its just there to check and see if you have a functioning cat.

toyme
03-07-2005, 01:05 AM
Hi im new in the forum... :evillol:

I have an accord with an h22a4 with a little probleme i would like to know how to bypass the 2nd o2 sensor on car.

and would like to know IF you don't do that what can it arrive ....?

And what is the symptom ???


Tx all :icon16:

What kindna problem you got?

The function of 2nd O2 is just to monitor the oxygen contents down stream or after the cat converter. Your computer need it to monitor the cat converter. it will activate cel only when your cat is no longer working efficiently.

its a good shit to have and I think you shouldnt fuck with it.

Greenblurr93
03-07-2005, 01:18 PM
if u got to www.o2simulator.com (http://www.o2simulator.com) and order one of their o2Sims, that will trick your ecu into thinking your cat is functioning properly, and theyre cheap.

sivic02
03-07-2005, 01:45 PM
if u got to www.o2simulator.com (http://www.o2simulator.com) and order one of their o2Sims, that will trick your ecu into thinking your cat is functioning properly, and theyre cheap.

My way is cheaper!

I am going to laugh if this has nothing to do with what the guy was asking because im still not sure what he was talking about.

superbluecivicsi
03-07-2005, 01:54 PM
This is the hardest post ever to decipher...if you do have a check engine light, which I am assuming is why you want to bypass it. You can buy an o2 simulator as stated above for 60 bucks or however much those things are. Or you can buy a set of spark plug non foulers for about 4 bucks at an auto parts store, drill out the end of one, put the o2 sensor in it, screw that one into a second non fouler, and screw the two together into the cat. So it goes o2 sensor, drilled out non fouler, regular non fouler, cat. Just pushes the o2 sensor further away from the exhaust flow so it thinks you still have a working cat.

i dont see how the o2 sensor still is able to read the o2 content and still not throw a CEL in this way. elaborate more.

sivic02
03-07-2005, 02:01 PM
http://www.k-series.com/forum/showthread.php?t=8833&highlight=mechanical

Thats where I heard about it. The idea behind it is when you remove the cat the 2nd o2 sensor is going to have too much crap reaching the sensor that isnt filtered out, which will make it think the cat has gone bad. What this does is it moves the o2 sensor further away so a limited ammount of exhaust gets to the o2 sensor, it is a VERY little ammount that actually gets to the sensor but as long as it is considerably less than the primary o2 sensor then it wont cause a CEL.

If anyone sees this and decides to do this instead of drilling the hole with a 1/2 drill bit im not great at drilling a straight hole and 1/2" is about the whole non fouler, I used a 1/4" bit and it worked just fine so if you dont feel comfortable about using a 1/2" bit you can go smaller.

Greenblurr93
03-07-2005, 02:20 PM
i hate to break it to you, but your way.. even though its logical, wont work, the o2 sensor also reads temp, and if it gets ANY chane in temp, it will throw a CEL. The Sim keeps the o2 sensor in the same spot, and its still functioning, but the sim changes the code it send to the ecu, so the ecu thinks eveything is stock, but the sim doesnt change the temp readings. oh and the Sim is $30 shipped.

sivic02
03-07-2005, 02:53 PM
Hate to tell ya but it does work. I have had mine on my car for around 10k miles and there are plenty of others who have had theirs on their car for much longer than that. And still no CEL ;)

Greenblurr93
03-07-2005, 04:49 PM
well then my friend... you proved me wrong and beat the system, congrats. why dont you post a pic so anyone that wants to know how to do it can have a pic and a description to help.

sivic02
03-07-2005, 05:03 PM
http://www.k-series.com/forum/showthread.php?t=8833

superbluecivicsi
03-08-2005, 08:17 PM
pretty good. looks like a pretty effective mechanical o

superbluecivicsi
03-08-2005, 09:19 PM
looks like a pretty effective mechanical o2 sim. in the end, any o2 sim will not get you to pass the sniffer. the sniffer measures more than just o2. if your CEL was thrown for a reason, then the reason needs to be fixed to pass the sniffer. assuming your state uses the sniffer.

im curious though, the application is on an oem cat................correct? no applications on a test pipe or hi flo cat.....................they have alot more non restrictive exhaust flow, which will increase the amount of o2 in the exhaust stream.

sivic02
03-08-2005, 09:30 PM
The write up was done on a test pipe. There isnt any need to do it on an oem cat unless its just shot or gutted. I have mine on my test pipe.

I have no emissions or any kind of testing here in south carolina, didnt in georgia either. Gotta love the south...they cant do standard check ups on cars because 90% of the people wouldnt be able to drive their smokey oldsmobiles or gmc pickups with no headers.

big10spice
01-03-2009, 10:25 PM
Does this work on any type of car/truck? I want to take the cat off my 05 dodge ram but i wasnt sure how to by pass that second sensor.

Greenblurr93
01-03-2009, 10:42 PM
please check thread dates before posting and dont bring up old threads. and to answer your question, visit: o2simulator.com for various ways of bypassing the o2 sensor for your truck.

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