Mazda CX-9 Grand Touring 2009 Manual page 1357

NO.15 EMISSION COMPLIANCE [MZI-3.7]
NO.15 EMISSION COMPLIANCE (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
15 EMISSION COMPLIANCE
DESCRIPTION Fails emissions test.
POSSIBLE
CAUSE
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Vacuum lines leakage or blockage
Cooling system malfunction
Spark plug malfunction
Leakage from intake manifold
Erratic or no signal from CMP sensor
Inadequate fuel pressure
PCV valve malfunction or incorrect valve installation
Exhaust system clogging
Fuel tank ventilation system malfunction
Fuel-filler cap malfunction
Charcoal canister damage
Air cleaner element clogging or restriction
Throttle body malfunction
Erratic signal to ignition coil
Improper air/fuel mixture ratio control operation
Bend or open circuit HO2S wiring harness
Catalyst converter malfunction
Engine internal parts malfunction
Excessive carbon is built up in combustion chamber
Improper engine compression
Improper valve timing
WARNING:
The following troubleshooting flow chart contains fuel system diagnosis and
repair procedures. Read following warnings before servicing fuel system:
Fuel vapor is hazardous. It can easily ignite, causing serious injury
and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and cause
serious injuries or death and damage. Fuel can also irritate skin and
eyes. To prevent this, always complete "BEFORE SERVICE
PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this
manual.
(See BEFORE SERVICE PRECAUTION [MZI-3.7] .)