2003 Dodge Ram 1500 P0172 - Poor Fuel Mixture and Check Engine Light Issues
I have inspected the fuel injectors and confirmed they are functioning properly and delivering adequate fuel flow. The vehicle is exhibiting a persistent P0172 code, indicating an excess of unburned fuel in the intake system. After initial troubleshooting, I removed the Mass Airflow (MAP) sensor to inspect it. Upon disassembly, I observed significant black buildup inside the center tube that extends into the intake manifold. I cleaned the sensor thoroughly and tested its vacuum seal — it held vacuum properly. However, after reinstallation, the check engine light activated immediately. A scan tool revealed a new code: P0108 — MAP Sensor Circuit Voltage Too High. I replaced the MAP sensor with a new one at a cost of $28.13. After the replacement, the vehicle's performance improved and the P0172 code did not reappear. This suggests that cleaning the sensor may have loosened internal components or caused a temporary malfunction. I believe this case highlights the importance of proper diagnosis when addressing P0172 in 2003 Dodge Ram 1500 models.
I removed the MAP sensor and found substantial black buildup inside the center tube that extends into the intake manifold. After cleaning it, I tested the vacuum seal — it held properly. However, after reinstallation, the check engine light turned on immediately. A scan revealed P0108 (MAP Sensor Circuit Voltage Too High). I replaced the sensor with a new one for $28.13 and the issue is now resolved. This indicates that cleaning may have damaged or loosened internal components. Thanks to everyone, especially Kev2, for the helpful insights.