- Joined
- Jan 21, 2023
- Messages
- 145
- Reaction score
- 83
- Points
- 28
- Location
- sherwood Oregon
- Vehicle Year
- 2005
- Make / Model
- Ranger XL
- Engine Type
- 2.3 (4 Cylinder)
- Engine Size
- 2.3
- Transmission
- Automatic
2.5 engine block 2.3 head with OEM ECU for the 2.3. I built this engine about 3 months ago and have about 3K on it. When first built it ran with multiple misfire codes and replaced plugs, wires and OEM coil. It cleared the code problem for about 2500 miles. The PO300 code is back this morning. There is no noticeable change in engine and runs smooth. So after a few pages of reading I am thinking, 1 fuel injector problem 2 Catalytic converter 3 O2 sensors, vacuum leak? Ideas on diagnosing this misfire issue before I throw more parts at it??