Plx wide band

[gteatr6]

Can you replace the stock o2 with the plx wide band and use it for the ecm input also since it has narrow output capability?

 

[MikeL.]

Not in the stock location. IIRC, it needs to be in the bend of the down pipe. The exhaust gasses must be too extreme for the plx in the Stock locale.

 

[gteatr6]

Has anyone tried it in the stock location? Any data available?

 

[Sweet6]

my buddy stuck in the stock location just to try it. It seem to work fine.

 

[aminga]

The sensor won't live long there.

 

[Sweet6]

Been on 2 years so far lol

 

[blackturbocars]

I will work and display actual a/f ratio for non boosted conditions. Under boost the reading will be wrong, and the sensor life will be shortened.

 

[gteatr6]

Why would the readings be off under boost in the stock location?

 

[blackturbocars]

The sensor is designed to operated in near atmospheric conditions. The back pressure in the headers will dilute the reference gas. (The outside air/oxygen) The narrow band sensor operates the same way and is not used by the computer when under boost.

 

[blackturbocars]

Wideband Lambda sensors primarily count oxygen atom numbers through measuring the oxygen ion current within the molten electrolyte of the sensor’s pump cell. The exhaust gas pressure affects this oxygen ion current – more pressure means more atoms per unit volume and a higher current at the same Lambda. At a higher exhaust gas pressure
a rich reading will appear richer than it really is, and ...
a lean reading will appear leaner than it really is.
This is the main reason you should position the sensor after the turbo where exhaust back-pressure is lowest.

 

[blackturbocars]

........ to be clear, yes you can use the PLX narrow band output as the input to your ECM with the wideband sensor installed ahead of the turbo, just remember the "under boost" the indicated a/f ratio will not be correct.

 

[hiboom]

The sensor is designed to operated in near atmospheric conditions. The back pressure in the headers will dilute the reference gas. (The outside air/oxygen) The narrow band sensor operates the same way and is not used by the computer when under boost.

Then how do I get a reading on my scan master of my o2's (780-800) just thought maybe I'm missing something.

 

[TurboDave]

You can do as I and many others do. Leave the stock narrow band in it's proper location and it will feed the car's ecm for idle and cruise closed loop operation, and you can also read it during WOT operation and look for your 780-800 values (although, when you get a wideband hooked up you'll see that those values are horribly rich).
Then mount the wideband in its own bung somewhere downstream of the turbo and monitor your wideband O2's that way.

 

[Ttype6]

Then how do I get a reading on my scan master of my o2's (780-800) just thought maybe I'm missing something.

The .780,that is commonly sought after in the turbo Buick community,is the number you should see at the top of third gear as the car crosses the finish line. In other words,you have to run a complete quarter mile from a standing start and note the O2 number as you cross the finish line. The O2 number you see,as you leave the line,will be much higher. Perhaps .835. It will continually fall during the run until the end of race at the finish line. This phenomenon is a result what blackturbocars has described. The WOT A/F ratio doesn't change during the quarter mile run. The high heat and pressure cause the O2 sensor to give an inaccurate reading. When you have a wideband mounted downstream,you'll see that the WOT readings will remain the same throughout the run. The most important thing to learn from these facts is,if you see .780 as soon as the boost comes up at WOT,you are lean.