O2 eliminator [Merged 11-8] removal sensor cel disable

[~97TalonTSi~]

This may be a newbie question, I have never really thought of doing this until now. My question is why remove the O2 sensor? Which one is removed? Are there any electrical parts to the removal? The reason I am asking is I will be getting the AGP L2R soon and Kevin recommended a 2.5" tubular o2 eliminator. So I guess I just need some info on what the benefits of removing the o2 sensor are.

Thanks

 

[Stapl3]

you dont need a 40 dollar unit youcan go to radio shack and get the parts for literally $2 hide all the wires and connectors under your coinsole next to your shifter. i had a full 3 in piping intoa real apexi n1 with 3 in inlet and never got a cel either youprobably never will because the sensor is right after the cat as long as you have a cat or the o2 eliminator installed you wont get a cel. both my cars are catlessand no resonators.

Let us know what you used. When I tried to do this, the needed resistor/capactor (i forget which) wasnt available from radioshack and cost almost 20 dollars.

The sensor is heated, so you will need a heatsink or expect a fire. This is not a simple thing.

 

[kottyking]

you dont need a 40 dollar unit youcan go to radio shack and get the parts for literally $2 hide all the wires and connectors under your coinsole next to your shifter. i had a full 3 in piping intoa real apexi n1 with 3 in inlet and never got a cel either youprobably never will because the sensor is right after the cat as long as you have a cat or the o2 eliminator installed you wont get a cel. both my cars are catlessand no resonators.

Thats great that you have that exhaust, but what did you use for the question asked above?

 

[Stapl3]

Also, it doesn't matter what exhaust you have or if you even have one. I ended up using a worm gear clamp attaching it to the outside of my exhaust pipe, worked like a charm until a rock nailed it. The ECU just looks for it to be plugged in electrically and that is all. It doesn't care what it's attached to.

 

[kottyking]

So basically u just need it plugged in?

 

[DiamondStarM]

no, if its plugged in and the reading is not correct it will throw a CEL, you have to do the resistor mod on the vfaq to simulate the signal the ecu should be reading

 

[Stapl3]

This is false. I and all the locals have simply had it electrically plugged in and attached to the outside of our exhaust pipes. The front o2 does all the work, the rear o2 is strictly emissions and along for the ride. It wants to be electrically plugged in and nothing else.

 

[boostin_2_high]

This is false. I and all the locals have simply had it electrically plugged in and attached to the outside of our exhaust pipes. The front o2 does all the work, the rear o2 is strictly emissions and along for the ride. It wants to be electrically plugged in and nothing else.

Exactly

 

[kottyking]

So as long as its plugged in its all good in the hood and it'll only throw a code if the sensor is "unplugged". (Just wondering, I dont have a 2g but I've been looking at getting one so I wanna know)

 

[cfisher]

I got a CEL as soon as I installed my turbo back. The o2 sensor works just fine but I get a P0136 for o2 sensor bank 2. The sensor is plugged into my exhaust. I'm just going to do the vfaq mod and be done with it.

 

[DiamondStarM]

This is false. I and all the locals have simply had it electrically plugged in and attached to the outside of our exhaust pipes. The front o2 does all the work, the rear o2 is strictly emissions and along for the ride. It wants to be electrically plugged in and nothing else.

Sorry but youre wrong. Explain to me why they even put the second sensor in then, just to complicate things. If you have no cat and you install the second o2 sensor connected and working you will get a CEL just like cfisher above because your second o2 sensor checks that the cat is working and since its not there it thinks its not working and you get a CEL, thats why the vfaq mod tricks the computer with the resistor, giving it a reading in the "acceptable" range.

 

[Stapl3]

If you have no cat and you install the second o2 sensor connected and working you will get a CEL

Based on what? This proves false in my personal experience, and try telling that to 6 local 2g guys with their rear o2 sensors ziptied to their exhaust hanger.

Cfishers is probably not working. They are sensitive as hell, something probably happened when touched.

It is strictly emissions. Who knows why obdii has it. How many times do you see someone put a test pipe on and get a cel? Almost never. Remember, a cat is emissions, and if it's looking for one, it does a terrible job.

I'm going off my personal experience, 6 local 2gs, and what I have read on dsmtalk.

 

[DiamondStarM]

You are right that the rear o2 is for emissions, I explained above how it works and how and why it causes a CEL. I told you why OBDII uses the second sensor....

 

[My96AWD]

Mine was zip tied till it fell and got ripped of by something. no problems till then. Also you can wrap it with alum foil and thread it back in.

 

[Stapl3]

I think the foil trick is only to protect it from the elements. Mine was fine until a stone hit it on a dirt road, then it was just a matter of buying a new one. Foil probably would have saved it.

 

[exzercist]

Based on what? This proves false in my personal experience, and try telling that to 6 local 2g guys with their rear o2 sensors ziptied to their exhaust hanger.

Cfishers is probably not working. They are sensitive as hell, something probably happened when touched.

It is strictly emissions. Who knows why obdii has it. How many times do you see someone put a test pipe on and get a cel? Almost never. Remember, a cat is emissions, and if it's looking for one, it does a terrible job.

I'm going off my personal experience, 6 local 2gs, and what I have read on dsmtalk.

the rear o2 will pick up that there is nocat the o2 voltage will be around .90 and goes up and down like the front does. as soon as the rear o2 reads that high it will trigger a CEL. both my 96 tsi and 98 gst both threw CEL almost instantly when installed the 3in ss downpipes with no cat. if you 6 local 2gs dont throw codes then there cars are screwed up.

 

[MarsaGSX]

I think the foil trick is only to protect it from the elements. Mine was fine until a stone hit it on a dirt road, then it was just a matter of buying a new one. Foil probably would have saved it.

I read lots of threads about 2nd O2 eliminator....read about some "Alternative mode" since is out a exhaust
So, you sayin stay plugged and can zip tied on hanger or can put inside car..NO CEL,NO "Alternative mode" Everything

 

[cfisher]

the rear o2 will pick up that there is nocat the o2 voltage will be around .90 and goes up and down like the front does. as soon as the rear o2 reads that high it will trigger a CEL. both my 96 tsi and 98 gst both threw CEL almost instantly when installed the 3in ss downpipes with no cat. if you 6 local 2gs dont throw codes then there cars are screwed up.

I had no CEL until I threw in the 3" turboback. As soon as I started it up after the install I got a CEL right away P0136. My logger states it works just fine but after clearing the code it comes back.

 

[Stapl3]

Don't take it the wrong way fish. If you set it on the ground in a way it doesnt like or use a hammer and wrench to get it off or something dumb like that it will hate it. They are very delicate.

 

[Stapl3]

or can put inside car..NO CEL,NO "Alternative mode" Everything

The sensor is heated. Putting it inside the car on the carpet is an exremely poor idea.

 

[Black95TSIawd]

I wrapped my rear o2 up in a bag and some tape so it doesnt get wet and ziptied it underneath the car. No CEL. Once the o2sensor got wripped up in the snow and i dragged it around for a couple days, the cel came back. I put another one on and did the bag thing again, this time making sure its more secure and not so low, CEL never came back. I actually have my wideband sensor in its place.

 

[eclipsegsx1736]

I've had my car with no cat for about 6 months now, no CEL. The sensor is still plugged into the catback. The rear O2 sensor only tells if your cat is functioning properly and doesn't affect anything else, other than throwing a CEL. It's funny that installed this $100 sensor in my car for one simple, specific purpose, and it didn't even do it's job. (no cat and no CEL)

 

[Boiler2]

My shop manual says:
- If the rear O2 sensor fails, the car will perform closed loop control based on the front O2 sensor.

I will have to read further since I thought the car only uses the front sensor anyway for closed loop control. I have had mine zip tied under the car for a few years and get a CEL about once a year. My gas mileage is about 24mpg so I definately must be OK.

For the non-turbo, my manual says if the downstream O2 sensor fails, the car will operate in open loop. Maybe this is where people get confused and mis-state information.

I really think people should buy and read the mitsu shop manual for the truth. Just to add to the above ... there are apparently 2 closed loop control methods. The first uses both the front and rear O2 sensor. The second uses just the front O2 sensor if the rear one fails. If the front fails, the car operates in open loop. This is from the 97-99 manual. Maybe the 95-96 is slightly different?

The rear O2 is there for a reason and just having it plugged in will not guarantee you do not get a code. After a bunch of initial criteria is met, the ECU checks the following:
-That the voltage from the O2 sensor is not lower than 4.5 volts when 5 volts is applied to the sensor output line via a resistor.
-That when making the AF ratio 15% richer, that the sensor output voltage goes beyond 0.1 volt.
If either of these fail, a CEL is thrown. There are a few other comments and criteria for other similar codes. Too much to list here.

 

[domenico_169]

k, i am about to get an exhaust made for my car, would the best thing technically to do is get a bung and just get them to install the o2 sensor there?

 

[DiamondStarM]

Even if you have a bung with the rear o2 sensor in it wont matter if you have no cat. You will still need to do the vfaq mod for it because the rear sensor will have the same reading as the front which will throw a CEL. If your custom exhaust has a cat you might be ok depending on if its really a cat or just one of those cat shaped resonator they sell on ebay that dont really perform the job of a cat.

 

[domenico_169]

ya im just going to be putting in a normal resignator to quiet the car down. So technically there is no purpose of even putting it in then? jus tzip tie it up and do the mod?