2004 Jeep Grand Cherokee Limited 4.7L V8 OBD2 Fault Codes P0300-P0356 and P0141/P0161 - Engine Stalls, Rough Running, Gas Fumes

Model: 2004 Jeep Fault Code: P0300 Posted: 2013-05-26 00:02

My 2004 Jeep Grand Cherokee Limited 2WD with a 4.7L V8 engine and automatic transmission is exhibiting severe engine performance issues. The vehicle ran fine initially but suddenly stopped during cranking. After restarting, the engine runs roughly, frequently stalls, and emits strong gas fumes. Vehicle details: - Model: 2004 Jeep Grand Cherokee Limited 2WD - Engine: 4.7L V8 (J VIN) - Transmission: Automatic - Modifications: Stock - no aftermarket parts or modifications - Odometer: 88,474 miles Diagnostic codes retrieved: - P0300 (Random/Multiple Cylinder Misfire) - P0301, P0302, P0304 (Individual cylinder misfires - cylinders 1, 2, 4) - P0353, P0352, P0356 (Ignition coil issues - coils for cylinders 3, 5, 6) - P0141 and P0161 (Oxygen sensor faults - bank 1 sensor 1 and bank 2 sensor 1) I performed a diagnostic test by disabling injectors and coil packs one at a time (cylinders 1 through 6). After removing each component, I observed engine performance. The engine ran on two cylinders with no improvement when components were reinstalled. This indicates the misfire is not isolated to a single cylinder or injector. Additionally, upon inspecting spark plugs, I found severe degradation: pitted electrodes and burned tips with a slanted appearance—consistent with being hit by a grinder at an angle—suggesting possible internal combustion issues or electrical arcing.