my 2003 accent keeps blowing ecm1 fuse and wont start

ECM1 fuse feeds the condenser and rad fan relays along with a variety of emission control components. First try pulling the rad relay and then the condenser fan relay. If that didn't work,since it blows before starting, it rules out other components like purge valves. My suspicion is that there is a short in the heater system in one of the 2 oxygen sensors. Disconnect both sensors and replace the fuse. See if the fuse blows when the key is turned on. If it doesn't, plug in 1 of the 2 and try again. If it blows, replace that O2 sensor, if not, plug in the other and try again.