What is your setup?
I would think you want the open element sensor, I find that even with mine mounted in the middle of the intake tube it still heat soaks some. And being that it is density based, it will lean it out. How much authority do you give the ECU for correction? It should be able adjust for this and still have decent power.
Is the AFR noticeably changing, or is it something else?
1995 GTI VR6 - 12.90@106 R32 power - 12.833@106 12v power
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