Inspect the cam chain guide in the following procedures:

Cam chain guide / cam chain tensioner
removal and installation
Cam chain tensioner inspectionDTC “c28” (p1655): secondary throttle
valve actuator (stva) malfunction
Detected condition and possible cause
Detected condition
Possible cause
The operation voltage does not reach the stva.
Ecm does not receive communication signal from the
stva. Stva can not operate properly or its motor locked
Stva malfunction.
...
Exhaust system components
Exhaust pipe gasket
Exhaust pipe assembly
Ho2 sensor
Connector
: install the connector so that the
chamfer side faces backward.
Muffler chamber
Muffler body
Excv cable no. 1
Excv cable no. 2
When loosening or tightening the pulley bol ...
DTC “c44” (p0130/p0135): ho2 sensor
(ho2s) circuit malfunction
Detected condition and possible cause
Detected condition
Possible cause
C44/P0130
Ho2 sensor output voltage is not input to
ecm during engine operation and running
condition.
Sensor voltage > 1.0 V
Ho2 sensor circuit is open or shorted to the po ...