Innovate's LM1 mounting instructions (read 4.1)
On TURBO CHARGED vehicles: Install the bung downstream from the turbo before the catalytic converter. The high exhaust pressure before the turbo interferes with
the lambda measurement and the high exhaust temperatures
encountered there can damage the sensor.
The Wideband Oxygen sensor must be positioned after the turbocharger and before the catalytic converter. Recommended installation
requires welding the O2 sensor bung in the down pipe at least 16” away from the turbo. A stock narrowband O2 sensor location is
usually too hot for the wideband O2 sensor. The oxygen sensor must be positioned vertically (wires pointing upwards between 10 and 2
o’clock) to prevent cracking of the sensor ceramic element and protect sensor against water condensation.
Jacob Electronics Comments:
"The oxygen sensor should be mounted in the downpipe, not in the collector.
The sensor should be at least 8 inches from the turbocharger. The extreme
heat and exhaust system backpressure found in the collector(s) of a
turbocharged engine can cause inaccurate air/fuel ratio readings and lead to
premature failure of the sensor."
"On turbocharged engines the UEGO sensor must be installed after the turbo charger, if not, the pressure differential will greatly effect the accuracy of the unit. In applications with a catalytic converter, the UEGO sensor must be mounted BEFORE the converter."
1987 911 cab, modified