Can anyone tll me what the difference is between a P1 engine and a normal 4dr impreza engine? Internally that is? A friend has had an unfortunate incident with number 2 piston, destroying the block in the process.

Thanx.

Ande.

 

AFAIK,the pistons are different,and the heads,other than that theyre the same(providing you have a phase 2).If you are going to use the orignal heads and ancillaries ,then you only need to change the pistons to sti forged (or other).

Its the same engine in an sti 5/6.

Do you know what caused the failure in piston 2?
Most people complain about piston 3.

Had a similar experience myself and it seemed to be the MAF sensor as the most likely culprit.