Subaru 2009 IMPREZA Service Manual page 961

FUEL INJECTION (FUEL SYSTEMS)
7. Knock Sensor
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the intercooler. <Ref. to IN(H4DOTC)-
13, REMOVAL, Intercooler.>
3) Disconnect the knock sensor connector.
4) Remove the knock sensor from cylinder block.
Knock Sensor
B: INSTALLATION
1) Install the knock sensor to the cylinder block.
NOTE:
The portion of the knock sensor cord that is pulled
out must be positioned at a 60° angle relative to the
engine rear.
Tightening torque:
24 N·m (2.4 kgf-m, 17.7 ft-lb)
IN-00203
2) Connect the knock sensor connector.
FU-03437
3) Install the intercooler. <Ref. to IN(H4DOTC)-13,
INSTALLATION, Intercooler.>
4) Connect the ground cable to battery.
FU-03825
FU(H4DOTC)-36
(A) Front side of vehicle
FU-03826
FU-03437
IN-00203