DevinWolfe

As the topic reads, I am running an aftermaret header. I will be installing a downpipe and a wideband O2 sensor in the upcoming week. Being that the factory O2 in the downpipe is not going to be seeing a difference from upstream and downstream exhaust gasses, do I really need to keep it on the car?

Is there some way to short the circuit to read an "OK" signal so that I may use the factory location (on the aftermarket pipe) for the wideband O2? I would really prefer not to have 3 O2 sensors unless I must.

If this cannot be done, or is not logical, then please let me know where the best location for the wideband O2 sensor would be.

Any help and/or comments are welcome. Thanks!

SoccerBoy_AP

Excellent Question!
I'd like to know too, because I'm eventually getting a wideband so I can properly tune. But so far I've been directed to making a new bung on the header for the new O2 sensor.

DevinWolfe

From what I can tell after researching a lot more, the O2 sensor in the header (or factory manifold) is necessary for the ECU to make fuel adjustments.

While the second O2 sensor is simply for emissions check purposes, it is really not doing a damn thing after you do the anit-fouler trick, so why not use that bung for the wideband sensor?

Would it be possible to leave the factory O2 sensor hooked up and tucked away somewhere under the car outside of the pipe? My thought is that in fresh air it would not be exposed to the chemicals that would let the ECU know that the cat is gone.

bkuhl

iTrader: (1)

it measures the o2 level difference between the two sensors. if the data passed is not between the threshold parameters, it will trip the CEL.

2_much_tc

I believe you need both 02 Sensors. Just weld another bung on the s-pipe and be done with it. You don't want to cause any additional problems if you don't have that second 02...

DevinWolfe

In that case does the wideband O2 need to be in any particular area? An old Supra buddy of mine said that it needs to be within 3 inches (downstream) of the collector on the header, does this sound correct? I don't think it would matter as the exhaust only loses a few degrees in that short distance.

Do exhaust shops usually keep these bungs on hand? I cannot seem to get one at any of the usual parts stores. Advance, autozone, or oreillys.

bkuhl

iTrader: (1)

common place on the tC for a wideband O2 gauge is on the S-Pipe on the bend before the secondary O2

2_much_tc

^ I believe it is after the sensor on your s-pipe. TCPETE made a thread about it too, and he came to the conclusion it was after.

SoccerBoy_AP

The closer to the engine exhaust outlet = more accurate O2 sensor readings.

caveman

Your stock A/f sensor is on your header , and your o2 sensor is on your s-pipe.....

When puttin a wideband in, you need to weld another bung onto the s-pipe and install the sensor in the secondary bung....both stock sensors are necessary!!!!


and 2 much tc is correct about the thread