I had real trouble finding a suitable alternative oxygen/lambda probe for my 1992 Rev 2 MR2 Turbo. I can’t find the original Denso part number at the moment, but I managed to find that a Denso DOX-0107 fits the flange size correctly and is 1-wire, it just requires soldering to the original connector. It’s got a Flange 44 type flange which apparently matches the 3SGTE.
I got it from http://service-parts.co.uk/denso-oxygen-sensor-dox-0107
Manifold Absolute Pressure (MAP)/ Manifold Pressure sensors are used to determine the pressure of the air inside the inlet manifold, just before it enters the engine inlet ports. This is generally measured between the Throttle Body and the intake ports on a naturally aspirated engine, and between the turbocharger compressor outlet (after the Intercooler) on turbocharged or supercharged engines.
GM/Bosch Manifold Absolute Pressure sensor
The Intake Air Temperature Sensor (IAT) on an engine is primarily used in combination with a Manifold Absolute Pressure (MAP) sensor to determine the density of the incoming intake air.
Example Intake Air Temperature Sensor