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Old 11-01-2006, 04:00 PM   #1
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Default O2 Sensor Location

If the O2 sensor move further away from the turbo, will location affects the ecu? Huey (91 BRG) currently has a Greddy turbo, ETD manifold, stock ecu, Greddy Blue Emanage, 330 injectors. I am thinking of buying Tony's downpipe and relocated the O2 sensor further down the downpipe for easier replacement of the O2 sensor. Any knowledge on this would be appreciated.
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Old 11-01-2006, 04:10 PM   #2
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I think you'll be perfectly fine if you are running a 4 wire O2 sensor. If running a 1 wire you might find that until the car really warms up it will run a little rough.
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Old 11-01-2006, 04:25 PM   #3
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Thanks for the fast reply. I am currently using a 4 wire O2 sensor.
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Old 11-01-2006, 04:35 PM   #4
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The o2 sensor measures the amount of fuel in the exhaust gas, which is a byproduct of combustion and is not altered as it passes through the downpipe and midpipe. Therefore, it should not matter where the sensor is located provided that it is pre cat and there are no leaks.

I would have tony install the sensor bung at 12:00 high, 8-10" before the cat (the cat gets real hot). This position should promote longer sensor life and you have a perfect spot for a wideband sensor if/when you go that route. From recent personal experience, idle is much smoother with a heated sensor in this location (mine is a wb though). But since your car is brg, all bets are off .

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Old 11-01-2006, 04:46 PM   #5
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yeah work with tony, he can put it where you'd like. My stock o2 sensor used to be just off the turbine housing (3-4 inches), and I had no problems with cold starts.
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Old 11-01-2006, 11:21 PM   #6
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if you have a 4 wire youll be fine...

when i had my 1 wire i could actually log it cooling down and being useless at idle within 10 seconds of idling, this was placed down beside the gear box...so i switched to a heated sensor and all is good now....

so if your O2 is more than 6" from the turbine outlet you need a heated sensor!
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Old 11-03-2006, 07:16 PM   #7
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Quote:
Originally Posted by Ben View Post
The o2 sensor measures the amount of fuel in the exhaust gas
Ben
You sure the O2 sensor doesn't measure O2? <G>

FM has a temporary setup that they use for quick tuning. It is an O2 sensor that they stick right in the end of the exhaust. Bill says that there is only a VERY SLIGHT difference in O2 levels post cat. If you think about it, every time you go to the dyno (those of you with cats) you are using post cat gasses to tune.

Personally, I don't have a cat and installed my WBO2 as far away from the turbo as I could (which was about 1 inch after my downpipe).
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Old 11-04-2006, 10:57 AM   #8
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the theory behind the tailpipe o2 is that at near-WOT you've got so much flowing through it's not all caught in the cat (cats work best at cruise where most of us drive all day long--beyond that they get overwhelmed).

but for tuning i would put it before the cat. and remember there is a lag between the sampling and corrections. so if it's too far, it might be reading yesterdays o2 values instead of right now.

that said, I have mine about 15-18" from the turbo in the DP.

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