01 Boxster hood latch
 

I replaced the battery and now the hood pops open every time I open the door with the key. In addition, the hood pops up after 10 minutes of driving (intermittently) for no apparent reason. Fortunately the manual release continues to hold the hood down! I took out the hood latch and it was very stiff (like it was binding) so I went ahead and replaced it but the problem remained. I also disconnected/reconnected the battery and reset the radio code to no avail. I'm stumped - anyone have any ideas?

Well, there are two ways to open the hood.
Using the remote button, or the hood switch inside the car.
Could be that one of the two is broken, and create contact on movement.
Try to narrow the problem by eliminating one of the two.
I would start with driving the car without the remot ( remov the battery from the remote and drive the car using the key only).
If problem disappear, you will have to fix/replace you remote.
If problem continues, move to the next step and disconnect the switch inside the car.

Good luck.

Tried that ... hood pops open when the key is used in the door with the battery removed from the remote. Also tried locking the doors while driving but it had no effect either.

The mechanic that changed the battery slammed the hood harder than I like but as I said, I replaced the hood latch mechanism which included the electronic release with no change.

Appreciate any thoughts you have.

Thanx - Stan