Won't start after O2 sensor change

[Fritchit]

Hello All,

 

Ok, I just changed the O2 (post cat) sensor on my wife's 2003 Accord 4 cyl. Used a Denso sensor. After install I disconnected the battery for a few seconds to clear things out. Now the car won't start. I get the clickety-clicking sound then nothing. The immobilizer indicator (key icon) is flashing so I suppose the immobilizer is engaged(?) We actually only have the valet key for the car as both full function keys have gone missing over time.

 

Question 1: Does this sound like the immobilizer has engaged? I didn't think the car would make any noise at all if that was the case.

 

Question 2: Does this mean I need a go get a new key from the dealer? Any idea how much that will run?

 

Thanks if advance for you help,

 

Tim