I recently bought my first Subaru Impreza its a 1999 1.6 Lr. It started fine with no problems with the key and ignition from over a month, I brought it to get welding done once done and I went to start the car it would not start and the key wont work, the steering lock was on and after 30 minutes of messing with it I finally got the key turned once and it started I drove it home and then when I got back and went to start it again the problem continued. Has any one else experienced this or know what could cause this. I can't tell if its the key being worn down or not, the immobiliser turns off when the key is inserted and the door locks work fine with the key

 

Sounds as it the key maybe worn, not depressing the tumbler pins fully in the barrel to release the steering lock......... or the lock has siezed.

The (ECU) immobiliser (red key image on dash) turns off as it recognises the transponder chip in the key.

 

Also recently bought an my00 sti and I've found the key to be tempremental. For me in the ignition if I push the key in too far it won't turn and guess it's gone past the correct point to engage the pins to turn. It took me a couple days to guage the right amount to push it into the ignition. I'm looking on getting a new key cut and if this makes a difference I'll reply again.

 

No spare key to test with?