My 2004 wrx will crank and crank but will not fire up. A little while ago it popped 2 codes: P1134 front o2 sensor microcomputer problem, and p0031. I replaced the front o2 sensor and car will still not start. I have also replaced the crankshaft sensor because i had a spare one sitting around. Now my fuel pump is constantly running when i turn the key, all it used to do was prime for a few seconds and turn off. I am getting spark and fuel. I am now stumped as to whats going on with it.