Wideband Sensor Location
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GLK350
Wideband Sensor Location
How important is the location of the O2 sensor? Many sources say as close to the collector as possible. But if I were to take my car to a dyno for tuning, they'd just insert their sensor in the tailpipe, and they'd tune off that. I'm thinking about installing as close to the engine as I can and that is still not a PIA to install, so maybe 2-3 feet down the engine. Does that seem fine?
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From: New Orleans Area
2015 E400 Sedan
on todays cars say after 2001 or so (forget when it started) you have o2 sensors before & After Cats (each side for 2 exhaust manifold engines).
The ECM uses the one Before Cat to read engine's Air to Fuel Ratio.
These are a certain distance from exhaust flange to be in best location where flow is well mixed from cylinders on that bank and o2 sensor an get good readings to come up with A/F ratio.
Vehicle Manufacture decides as they also have to consider Replacing this part while on vehicle.
The one after Cat is just to check Cat is working.
So if you have catless engine and just using O2 to control engine close to head as you can is best but in a place you can replace over time
Now if building a fancy track, drag etc car I would put an o2 Sensor on each cylinder header exhaust tube to be able watch each one cylinder but this takes some Fancy aftermarket ECM to be able to have that many o2 inputs.
engine Dynos tend to have them since that is their purpose to get most from an engine.
The ECM uses the one Before Cat to read engine's Air to Fuel Ratio.
These are a certain distance from exhaust flange to be in best location where flow is well mixed from cylinders on that bank and o2 sensor an get good readings to come up with A/F ratio.
Vehicle Manufacture decides as they also have to consider Replacing this part while on vehicle.
The one after Cat is just to check Cat is working.
So if you have catless engine and just using O2 to control engine close to head as you can is best but in a place you can replace over time
Now if building a fancy track, drag etc car I would put an o2 Sensor on each cylinder header exhaust tube to be able watch each one cylinder but this takes some Fancy aftermarket ECM to be able to have that many o2 inputs.
engine Dynos tend to have them since that is their purpose to get most from an engine.
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From: Arizona
Bentley Continental GT; AMG GT
How important is the location of the O2 sensor? Many sources say as close to the collector as possible. But if I were to take my car to a dyno for tuning, they'd just insert their sensor in the tailpipe, and they'd tune off that. I'm thinking about installing as close to the engine as I can and that is still not a PIA to install, so maybe 2-3 feet down the engine. Does that seem fine?
When I do a WIDEBAND (differentiated from an O2 sensor). I look for a location pretty close and convenient to the (one of the 2) front O2 sensor. Here is an example of one I did. I built and tuned an N/A engine 6.2L 430HP; supercharged it to 625HP. Because I had to double the output of the 43lb injectors to 80lb, I had to get new injector data correct and fueling correct in PE. The only way I will do a tune with that big a gain is with a permanent wideband.
On this particular engine I used factory CATS. The pics below show the left side. I placed another hole and welded in another bung almost at the same place as the O2 sensor. The factory O2 sensor is the blue arrow, the wideband goes where the red arrow is.
The big flange mounts up to the left side exhaust manifold and the two sensor mounts end up on a VERTICAL. With a vertical mount I don't have to be concerned that much with where on the circumference I place the new bung, just convenience for future service. If, however, the mount would have been on a horizontal, then it would be important the new mount be 3 or 9 o'clock at least, or higher, but not anywhere below 3 or 9 O'clock.
I usually use an AEM or Ballenger WB, BC they are compatible with my hack tune software and I can read them directly into both data logs and the edit SW.
BTW, the difference between an O2 sensor and a (good) wideband is like the difference between a battle ax and a scalpel.
Hope this all makes sense.
