DTC P0300, DTC P0301, DTC P0302, DTC P0303, DTC P0304, DTC P0305 Or DTC P0306 : Description

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, ECM can detect a misfire. The misfire detection logic consists of the following two conditions.

1. One-Trip Detection Logic (3-Way Catalyst Damage)
   
   On first trip that a misfire condition occurs that can damage the 3-way catalyst due to overheating, MIL will blink. When a misfire condition occurs, ECM monitors CKP sensor signal every 200 engine revolutions for a change. When misfire condition decreases to a level that will not damage the catalyst, MIL will turn off. If another misfire condition occurs that can damage the catalyst on a second trip, MIL will blink. When misfire condition decreases to a level that will not damage catalyst, MIL will remain illuminated. If another misfire condition occurs that can damage the catalyst, MIL will begin to blink again.
2. Two-Trip Detection Logic (Exhaust Quality Deterioration)
   
   For misfire conditions that will not cause damage to the catalyst (but will affect vehicle emissions), MIL will only illuminate after misfire is detected on a second trip. During this condition, ECM monitors CKP sensor signal every 1000 engine revolutions. A misfire malfunction can be detected on any one cylinder or on multiple cylinders.