Porsche 911 TURBO - 1989 Workshop Manual page 147

Exhaust System
REMOVING AND INSTALLING TEMPERATURE SENSOR FOR EXHAUST GAS
TEMPERATURE CONTROL
Removing
Unscrew fillister head screws of rear panel
and remove panel with weatherseal.
2. Disconnect 2-pole plug connection.
3. Unscrew hexagon head bolt on rear engine
guard.
4. Unscrew coupling and remove sensor.
26 -31
Printed in Germany -II. 1976