rear o2 sensor on custom exhaust

[just2asian]

Ok, so I was doing some research, and i still really can't get a clear picture on this. I have a 3 inch downpipe that I ordered, a catco, hi flow cat, and i am planning on getting a full custom 3" exhaust bent for my car. Do i need to just have a bung welded after the cat somewhere to install the rear o2 sensor without tripping a code?

 

[CanadianTSi]

Yes.

Although you don't really need it, the code affects nothing.

 

[cobb]

I dont have a cat and all i did was just drill a hole in the down pipe where the o2 sensor was on the stock down pipe and put it back in. So it was not out and it wasnt triping any codes.

 

[vengerfreak]

I would think if you don't run a cat it would still trip no matter where you put it at. I took mine off and it the cel stayed on. check on O2 Sims.

 

[Smokin80]

You have a couple of otions.
1. If you put a cat back in then just put the 2nd O2 after the cat and your done.
2. If no cat, Look on ebay or a fine dsm retailer and im sure you will find an o2 simulator.
3. Ill try and find the post but there are lots on here about making an O2 similator yourself.
http://www.dsmtuners.com/forums/showthread.php?t=221951&highlight=O2+Simulator

4. Get dsmlink and disable the dtc check for the 2nd o2 sensor. $$$$ (this is what i have now)
5. I originally did this and it worked fine and was super CHEAP. Go to your local parts store and ask for spark plug antifoulers. Take your o2 sensor with you and find one that the threads are the same. Buy 2 antifoulers and screw them together so that the 02 sensor is held out of the exhaust stream. ( you will have to drill out one of them for the sensor to screw all the way in. This will trick the ecu into thinking that the O2 sensor is reading a constant voltage and that the cat is working. Worst case scenario you spent 5 bucks and 10 mins of your time and it doesnt work. But, i have seen a few people(myself included) do this and have no problems

Hope this helps
Smokin80

 

[cobb]

I would think if you don't run a cat it would still trip no matter where you put it at. I took mine off and it the cel stayed on. check on O2 Sims.

Been running with no cat for about 5 months now with the o2 in the pipe at about the stock position and havent triped a cel.

 

[CanadianTSi]

As I already Said the CEL for no rear o2 affects nothing, I don't see why people worry about it so much...

 

[DSMDirkah]

Best way I have found is to go to Advanced auto and but a package of "Spark plug defoulers" Drill out the inside of it so the sensor can be threaded into it.. Then just thread the defouler in like you would regularly install the o2 sensor.. The defouler will make it so that the sensor never sees exhuast flow

The ghetto way I did on my 2g which is pull the wire through the floor ( its almost under the seat next to the front right seat bracket) hook the o2 sensor up and put it in a metal pan under your seat (the heater element will get hot so be careful) I was running no exhaust at the time and this worked

 

[Smokin80]

Best way I have found is to go to Advanced auto and but a package of "Spark plug defoulers" Drill out the inside of it so the sensor can be threaded into it.. Then just thread the defouler in like you would regularly install the o2 sensor.. The defouler will make it so that the sensor never sees exhuast flow

I already said this....

I originally did this and it worked fine and was super CHEAP. Go to your local parts store and ask for spark plug antifoulers. Take your o2 sensor with you and find one that the threads are the same. Buy 2 antifoulers and screw them together so that the 02 sensor is held out of the exhaust stream. ( you will have to drill out one of them for the sensor to screw all the way in. This will trick the ecu into thinking that the O2 sensor is reading a constant voltage and that the cat is working. Worst case scenario you spent 5 bucks and 10 mins of your time and it doesnt work. But, i have seen a few people(myself included) do this and have no problems

 

[TrystanGST]

As I already Said the CEL for no rear o2 affects nothing, I don't see why people worry about it so much...

Because in some places (like here in Illinois) any 96 or newer car (OBDII) is emissions tested by a scanner. If they see codes, you fail. Therefore a CEL for a dead or non-existant CAT is bad news come emissions testing time.

 

[donswan]

I'm running a tester pipe with the O2 sensor still there and I have had 0 problems, been fine with no codes for over a year.

 

[spyderturbo007]

Or you can go the cheap route and leave the rear O2 plugged in, zip tie it out of the way and wrap the end in aluminum foil.