One problem related to manifold/header/muffler/tail pipe has been reported for the 2012 Jeep Grand Cherokee. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Jeep Grand Cherokee based on all problems reported for the 2012 Grand Cherokee.
At approximately 120k miles I began to notice a slight tick coming from the driver side of the motor. Over the next 5k miles I changed the oil several times, swapped plugs, coil packs and injectors to rule out any potential issues. I also did a visual inspection of the exhaust manifolds. The problem persisted and got worse. There was also a consistent hesitation under medium to heavy throttle input. I'm now at 126k miles and had a check engine light - p0303 for cylinder 3 misfire. I have started disassembling the motor and noticed the lifter has seized and started destroying the camshaft.