I've got an '02 Sirion Rally II 1.3L with a P0135 code problem. I know it's got something to do with the oxygen sensor heater that's in the pre-cat (bank 1, sensor 1) sensor. I am wondering if anyone knows the whereabouts of this sensor in the engine bay? I'm having trouble spotting it. I've got the correct sensor to fix it and the tools to do it, I just cant find it. Any help on this issue is appreciated.