2005 Dodge Magnum RT 5.7L with P0300, P0152, and P0175 Codes - Check Engine Light Fluctuates in South Korea
I own a 2005 Dodge Magnum RT with a 5.7-liter V8 engine, currently at just under 50,000 miles. The check engine light has been intermittently coming on and going off—sometimes staying on for days, other times flashing for only minutes. When the light is active, the engine exhibits hesitation, stutters, and in rare cases, stalls at low RPMs. Under full throttle, it shudders and struggles to reach operating speed. The symptoms are more noticeable when the car is in gear compared to park. However, if I keep the engine running at around 250-2500 rpm while in park, the roughness disappears. I recently had the vehicle scanned and received three diagnostic codes: P0300 (cylinder misfire), P0152 (O2 sensor 2/1 circuit high), and P0175 (fuel system 2/1 rich). I am currently in South Korea, where the nearest authorized Chrysler/Dodge service center is about one hour away. I have basic mechanical experience and would like to attempt repairs myself if possible. I’m seeking clear guidance on what components to inspect or replace. The engine has never had a tune-up. Could a simple spark plug replacement resolve this issue? Additionally, the 5.7L engine is factory-programmed for 89 octane fuel, but local gas stations only offer 92 octane. Could higher octane fuel be contributing to the misfire or sensor readings? Any insights into troubleshooting these codes on a 2005 Dodge Magnum RT would be greatly appreciated.
Start by inspecting the connector and wiring harness for the O2 sensor located at the rear of the exhaust system—this area is prone to rubbing against the transmission crossmember. If the connection appears damaged or loose, it could cause intermittent signal issues leading to P0152. Once confirmed, replace the O2 sensor with a genuine Dodge OEM part. While you're working on it, consider replacing all 16 spark plugs—by 50,000 miles, they are likely worn and may be contributing to misfires (P0300). Spark plug replacement is a common fix for this model, especially when combined with O2 sensor issues. This repair is both feasible and cost-effective for DIYers on a 2005 Dodge Magnum RT.