Kia Rio engine stall, after mechanic repair now crankshaft check-engine light
So I recently bought 2007 Kia Rio SX with 105k miles on it from a private party. Never saw problem while test-driving before buying, but after buying the engine has died about 6-7 times in the 1000 miles I have driven so far.
The engine mostly died when stopped on a signal or when entering a driveway when you are not stepping on gas. The car would restart within a few seconds (2-3 attempts sometimes, sometimes just one attempt does it) and then run absolutely fine.
There was NO check-engine light all this time.
Now, I got some other repairs done by a local mechanic where I had to get serpentine belt and a couple other belts replaced, transmission fluids flushed, power steering fluid flushed etc.
I now notice that after getting car from him, the engine light is ON and it complains of "Crankshaft position sensor" per the code.
(i) Could the crankshaft problem be ONLY this mechanic screwing up something while he replaced those belts (serpentine etc)? And the problem for engine dying might be independent unrelated problem?
2) He claims his "cleaning" in that area (near MAP sensors) is now highlighting the car-engine dying problem -- and that the crankshaft sensor was THE actual reason all along. Is this possible?
He also quotes 2 hours worth of time to replace the crankshaft position sensor, while reading around leads me to believe it shouldn't take more than an hour for a Kia Rio 2007.
Appreciate any suggestions. thanks much.