Hi, all. Today I put the key into ignition and then could not turn the key through to start the car. Basically, it feels like you put a wrong key in the car. This happened before and now it becomes a little scary since I just moved into NYC and don't know anyone and anything yet. My car has more than 120k on it and the knock sensor is bad but I didn't fix it since it costs too much. Don't know whether it is related.
Thanks a lot.

 

Try spray lube into the lock. All things like locks hinges need maintenance...

KS may be bypassed, costs 5c, like this
see http://www.cardomain.com/ride/748507/9

 

Every nissan I have seen has a knock sensor code. The knock sensor will not turn on the CEL and is nothing to worry about. The key could be the key its self, the cylinder, or a couple other components. Try a diffrent key first.

 

Bad KS: lame engine, tiger only in the tank... carburettors/oldiesels =noKS.

 

Thank allyour guys for the replys. It turns out to be my stupidity or might be Nissan's.
Anyway, as far as I know, if you turn around your steering wheel after you shut off the engine, you would have my problem when you try to turn the key and start the car next time. It is just sth. locked automatically by the car.
To solve it, you can just do the reverse--moving the steering wheel a little and turn the key through at the same time---Yahoo!

 

The wider the wheels, the more probable it is to park on uneven spot where vehicle weight rests on one wheel edge. This edge spot 'shifts' as wheels settle gradually down, turning steering. This causes 'pressure' against the lock. Sometimes one needs 'all' muscle power to counter this 'pinch'. This is typical on all vehicles with steering lock [not Saab:]