I am reporting a persistent and safety-relevant defect in my 2012 Jeep Wrangler with the 3.6L Pentastar engine. The vehicle is experiencing misfires on multiple cylinders, especially cylinders 1 and 5, triggering codes P0300, P0301, and P0305. These misfires result in loss of power, hesitation, and rough idle, creating serious safety concerns during acceleration or highway driving. Despite replacing spark plugs, ignition coils, the crankshaft position sensor, purge valve, and both oxygen sensors, the problem continues. The vehicle has just 83,000 miles and is currently at a certified third-party repair facility. Multiple mechanics believe the issue stems from known defects in the left (Bank 1) cylinder head or valve train componentsa”an issue Chrysler previously acknowledged via TSBs and a 10yr/150k mile extended warranty on select VINs. I contacted Jeep Cares and requested goodwill support, but they refused to even discuss the issue because my Jeep is not at a dealership. This leaves owners like me with limited, expensive options despite being affected by a well-documented defect. Jeep forums and independent shops have seen widespread misfire problems on early 3.6L Pentastar engines, especially 2012-2013 models. I urge NHTSA to investigate this pattern of failure. The misfires impact driveability and safety, and the manufacturer has not offered sufficient resolution or consistent support to affected customers. Iam happy to provide additional information, documentation, or diagnostics.