So, while i was driving my 2002 WRX my spark plug ripped out of the threads and made my car undriveable. i took it to an auto shop and they put in some hela-coil and it worked for a couple of months then blew out again. So i have a couple questions. I would like to know how this could of happened and how i could prevent it? I would also like to know what i should do next? I have a couple of options. I could buy a jdm engine and just swap it out (most expensive), change the heads (approximately $600 each and would like to get 2), or swap my engine out with another model (i.e. legacy). Please any suggestions would be nice, also if you have another suggestion to fix it let me know. Thanks.