It matters on the offset. If you're looking at a 9" wide wheel though, the answer is no since there are no 17x9" wheels that have near enough offset. If you are looking at a Rota DPT or similar 17x9" wheel, the offset is +42 which is 11 less than stock. You would need to roll the rear fenders and if you want to fit that, more severe modifications may be required if you have a soft suspension (lowering springs and stock struts). I recommend you stick with 235/40R17. Forget the spedo, the gearing advantage of shortening your 5-speed is beneficial on it's own. Also, you can easily fit 235/40R17 on a 17x8" wheel which are very easy to find in a more respectable offset (+45 to +55, most are +48)
That all said, you can fit 245/40R17 on a wrx with stock fenders, you just need a stiff suspension and some high offset wheels. I have 17x8.5" +48 wheels for example, which would work. I put 255/40R17 on mine though, and I have some minor rear fender clearance problems...
04 STi 16G powered lagless fun
04 WRX: SOLD