I have always run mine in the top dump pipe section (where the stock O2 sensor sits) maybe 6" from the exhaust wheel. the sensor head sits about 10mm into the gas flow on my set up.

It has to get hot enough to burn off any carbon deposits, otherwise you'll be forever replacing sensors.

My sensors (Bosch LSU 4.2) are lasting 4 years before they begin to drift out of calibration. I use a Tech edge 2j1 controller, so I can simply unscrew the sensor & run it's free air calibration to re-calibrate an ageing sensor.

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[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]