I have a 2008 Buick Lucerne - 80,000 miles- that was recently in a front end crash. Now the car suddenly stalls out when it reaches highway speed, and it won't restart. Been towed 4 times. After waiting 4 hours or overnight it starts up without a problem.
Changed the crank sensor and the fuel pump. The check engine light indicates a problem with the catalytic converter. My mechanic says the catalytic converter is not related to the stalling out or problem in restarting.
Recently, it wouldn't start, first time ever - cranked but didn't turn over; later it started up without a problem.
The car has always started up and run well, but this problem appeared after the accident.
Make sure the Cat is not clogged up, even partially clogged cat can do that because the exhaust gases can not flow freely and they go back to the engine. Have your mechanic check the back pressure for the Cat.
