Suzuki SX4 Service Manual page 101

Condition
Excessive hydrocarbon
(HC) emission or carbon
monoxide (CO)
Excessive nitrogen
oxides (NOx) emission
Possible cause
Faulty spark plug
Leaky or disconnected high-tension cord "High-Tension Cord Removal and Installation
Faulty ignition coil with ignitor
Low compression
Lead contamination of three way
catalytic converter
Faulty evaporative emission control
system
Fuel pressure out of specification
Closed loop system (A/F feedback
compensation) fails (Poor performance
of ECT sensor or MAF sensor)
Faulty electric throttle body assembly
Faulty APP sensor assembly
Faulty injector(s)
Faulty ECM
Engine not at normal operating
temperature
Clogged air cleaner
Vacuum leaks
Camshaft position control (VVT) system
out of order (for engine with VVT
system)
Improper ignition timing
Lead contamination of catalytic
converter
Faulty EGR system
Fuel pressure out of specification
Closed loop system (A/F feedback
compensation) fails (Poor performance
of ECT sensor or MAF sensor)
Faulty electric throttle body assembly
Faulty APP sensor assembly
Faulty injector(s)
Faulty ECM
Camshaft position control (VVT) system
out of order (for engine with VVT
system)
Engine General Information and Diagnosis:
Correction / Reference Item
"Spark Plug Inspection in Section 1H"
in Section 1H"
"Ignition Coil Assembly (Including Ignitor)
Inspection in Section 1H"
"Compression Check in Section 1D"
Check for absence of filler neck restrictor.
"EVAP Canister Purge Inspection in Section
1B"
"Fuel Pressure Check"
"Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C" or "Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C"
"Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C"
"Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C"
"Fuel Injector Circuit Check"
"Air Cleaner Filter Inspection and Cleaning in
Section 1D"
"Engine Vacuum Check in Section 1D"
"Oil Control Valve Inspection (For Engine with
VVT) in Section 1D"
"Ignition Timing Inspection in Section 1H"
Check for absence of filler neck restrictor.
"EGR System Inspection (If Equipped) in
Section 1B"
"Fuel Pressure Check"
"Engine Coolant Temperature (ECT) Sensor
Inspection in Section 1C" or "Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C"
"Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C"
"Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C"
"Fuel Injector Circuit Check"
"Oil Control Valve Inspection (For Engine with
VVT) in Section 1D"
1A-51