O2 sensor location - a thought for discussion

[BrApple]

So I don't know if this has been discussed before but I don't recall reading anything about it.

So I believe that I read before how one down side of MSDS headers is that the upstream O2 sensors only read one cyclinder of each bank. A more ideal situation would be if the sensor saw all three cyclinders on a given bank.

I would have to figure that each cyclinder should be fairly similar to each other but I am not certain.

Now my thought was what if one just swaps the location of the up and down stream O2 sensors. With headers and mil-eliminators i can't see it making a difference. For my NPG turbo kit I did have an O2 sensor bung added to the up-pipe for the rear bank so that I could pass emissions. I have repalced all the O2 sensors and the harness should be more then long enough to make the swap.

So would there be any benifit to having the O2 sensors read the whole bank of the enigne over just one cyclinder? Would it be an issue having the sensor that far away from cyclinder head?

 

[mmc757]

A benefit would be ensuring that flows are balanced...A sensor isnt very big, but it takes up a large percentage of X-section for a single tube whereas on the larger combined tube it would be a much smaller percentage and would affect all cylinders equally.

I say try it. My understanding is that the big thing you need is enough distance between upstream and downstream to ensure a temperature difference between them.