One problem related to manifold/header/muffler/tail pipe has been reported for the 2018 Chrysler Pacifica Hybrid. The most recently reported issues are listed below.
This past Monday/Tuesday we have the u94 recall service performed, we also had the first recall update done a couple of months ago. U94 was completed, and no issues were noted with the catalytic converter. Car was picked up Tuesday, but Wednesday my wife (who normally drives the vehicle) noted that it smelled a bit like burning rubber when she was driving. I drove the car today to check things out and after about 45 miles of driving when I pressed the accelerator a bit deeper to maintain highway speed during a medium grade climb I didn't notice any increase in power. At the same time I heard a loud popping sound which I initially thought was me running over something in the road (there was truck tire debris). I let off the accelerator momentarily to check the road and ensure I wasn't hitting any rubber debris. I again pressed on the accelerator, but again only electric motor power, and no extra grunt from the ice. I even flipped the hybrid info screen to the one that shows the balance of power from the electric motor and ice. I pressed the accelerator a 3rd time and saw the electric motor indicator go to 100% power, and after a second or so the ice indicator also went to 100%, but still no extra boost of power. At this time I heard another loud pop or two, and started to smell smoke. I realized there was something serious going on with the car. I pulled off to the side of the highway and once the car was no longer in motion with airflow under the hood I could see a significant amount of smoke coming from under the hood. I jumped out and popped the hood and what I saw was the entire exhaust manifold / catalytic converter area was glowing bright orange and smoke was emanating from somewhere deeper in the engine compartment. I called 911, fortunately car did not catch fire. I contacted Chrysler corporate customer service, and car was towed to dealer.