Dropped a 2004 2 litre engine with low mileage in my 2003 Lancer. New engine ran rough. Noticed an extra vacuum line on the 2003, so decided there was an upgrade and put the 2003 fule rail and intake on the 2004. The 02 sensors in bank 1, prior to catalytic converter are also different. It appears there is a relay in line on the new one. An engine service code indicates the 02 sensor is bad. I believe we killed it by running the 2004 w the extra vacuum line open. My question is, should there be any difference in the 02 sensors?