I’ve got a story from upstate New York, where my '11 Nissan Sentra started knocking like crazy. Turns out the cat converter was acting up—got clogged with junk, common heard it. My buddy had the same troubles, cursed that thing till fixed. Poor baby needed a checkup badly. Better to stay ahead of it than be stuck roadside!
I’ve had my 2011 Sentra in Toronto, and my catalytic converter went out like, super fast. Drainage issue, lotsa trouble! Friends said heater core probs too. Real pain, but fixed now, phew!