Subaru 2009 IMPREZA Service Manual page 1418

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK SECONDARY AIR COMBINATION
VALVE.
Check the pipe between the secondary air com-
bination valve and cylinder head.
2 CHECK SECONDARY AIR COMBINATION
VALVE.
Race the engine at 2,000 rpm to check whether
or not the exhaust leak is heard.
Check
Is there damage or disconnec-
tion of the pipe?
Is there any exhaust leak?
EN(H4DOTC)(diag)-197
ENGINE (DIAGNOSTICS)
Yes No
Replace the pipe Go to step 2.
between second-
ary air combination
valve and cylinder
head.
Replace the pipe Repair the poor
between second- contact of ECM
ary air combination connector.
valve and cylinder
head.