Mazda MX-5 Miata Sport 2007 Manual page 2014

2007 ENGINE PERFORMANCE Symptom Troubleshooting - MX-5 Miata
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NO.15 EMISSION COMPLIANCE [LF]
POSSIBLE CAUSE & DESCRIPTION (EMISSION COMPLIANCE)
DESCRIPTION
2007 Mazda MX-5 Miata Sport
Visually inspect the
exhaust system part.
Is there any deformed
exhaust system?
Inspect for
contaminated MAF
sensor.
Is there any
contamination?
Inspect the MAF sensor
for contamination.
Is there any
contamination?
Is engine compression
correct?
Verify test results.

If normal, return to diagnostic index to service any additional

symptoms.
(See ENGINE SYMPTOM TROUBLESHOOTING [LF] .)
If malfunction remains, inspect related Service Bulletins and/or On-

line Repair Information and perform repair or diagnosis.
If vehicle is repaired, troubleshooting completed.

If vehicle is not repaired or additional diagnostic information

is not available, replace the PCM.
(See PCM REMOVAL/INSTALLATION [LF] .)
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Yes Replace the suspected part.
No Go to the next step.
Yes Go to the next step.
No Inspect for cause.
Yes Replace MAF sensor.
No Go to the next step.
Yes Inspect the valve timing.
No Inspect for cause.
EMISSION COMPLIANCE
Fails emissions test.
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