I had a leaking heater core in my 05 Impreza 2.5RS, so I got a replacement and started tearing into my dash. About an hour later I had the entire dash removed. I successfully installed the replacement heater core and put everything back together. After I finished buttoning everything back up I reconnected the negative battery terminal. Heater works only on fan setting 4 and now I have a host of new problems. When I turn the key forward to the 'ON' (not running) position the relays on the passenger side start clicking and the cooling fan starts to run for a few seconds at a time, shuts off and repeats. BUT WAIT, theres more! When I start the car I have a FLASHING check engine light. I pulled the code and they are the following:\nP1518\nP0851\nP1152\nP1153\nP0137\nP0502\nI had 0 Check Engine lights when I started, car was fine besides the heater core. I looked up some of the codes and 2 are for heated o2 sensor and starter relay, so I'm wondering if I didn't spill some coolant on the starter and o2 sensor when I was pulling the heater core lines from the firewall and mess something up. Maybe not. Wtf is going on here? Need help ASAP, thanks in advance.