Outline Of Diagnosis

Detect the presence of misfire occurrence.

Monitoring Misfire which influences exhaust deterioration (1.5 times of FTP) and catalyst damage is made obligatory by the law. Misfire affecting these two has three patterns below.

• Intermittent misfire (Different cylinders misfire intermittently.): FTP 1.5 times misfire
• Every time misfire (The same cylinder misfires every time.): Catalyst damage misfire, FTP 1.5 times misfire
• Opposed misfire (Dual ignition equipped model as #1, #2 simultaneously ignite. NA model only.): Catalyst damage misfire, FTP 1.5 times misfire

The following detecting methods are adopted for these detection.

1. Intermittent misfire: FTP 1.5 times misfire
   • 180° Interval Difference Method (3,550 RPM or less)
   • 720° Interval Difference Method (2,950 RPM or less)
2. Every time misfire: Catalyst damage misfire, FTP 1.5 times misfire
   • 180° Interval Difference Method (3,550 RPM or less)
   • Pattern Recognition Method (2,950 RPM or more)
3. Opposed misfire: Catalyst damage misfire, FTP 1.5 times misfire
   • 180° Interval Difference Method (3,550 RPM or less)
   • Pattern Recognition Method (2,950 RPM or more)