2002 Dodge Caravan 3.8L Engine Running Rich - P0172 Code Explained

The check engine light has been on for some time, initially showing an evaporative emission system code. Recently, however, I noticed the vehicle running very rough—especially when starting—and it would attempt to compensate by increasing RPMs. The diagnostic trouble code (DTC) is P0172, indicating a 'Bank 1 Running Rich' condition. Despite the rough idle and performance issues, this is not a misfire code but rather an oxygen sensor-related fuel mixture issue. My freeze frame data shows: - RPM: 2720 - Fuel System 1: Closed - Fuel System 2: Disabled (is this normal?) - Load Calculation: 43.1% - Coolant Temperature: 109°F - Short Term Fuel Trim: -13.3% (indicating lean condition, which contradicts 'running rich') - Long Term Fuel Trim: +7.0% (suggests a persistent fuel enrichment) - Intake Manifold Pressure: 20 inHg (note: original said 27 inHg, likely typo) - Vehicle Speed: 27 mph I initially suspected a MAP sensor issue due to the rough idle and erratic behavior. However, I've also observed that symptoms worsen during heavy rain. Upon inspection, I found the water drain tube under the right front cowl was disconnected—could this have contributed? While it may cause minor moisture issues, the current problem appears constant and not weather-dependent. Could this be a sensor calibration issue, fuel pump malfunction, or a vacuum leak? Any insights on diagnosing P0172 in a 2002 Dodge Caravan with a 3.8L engine would be greatly appreciated.