Old BMW Ignition Coil 12131247281, UF291 Replacement

For older BMW E46, E90 with N42/N46 four-cylinder engines (e.g., 318i, 320i), ignition coil replacement is OEM 12131247281 (UF291 high-voltage module replacement). Mounted above the cylinder head, directly connected to the spark plug to convert low voltage to high voltage. Installation difficulty: medium; labor 1–1.5 hours; remove protective cover and connectors. Symptoms of aging ignition coils include idle jitter, sluggish acceleration, engine fault light, or abnormal fuel consumption; replacement is advised.