I've just fitted a new O2 sensor to my new exhaust and fitted them to new O2 sensor bosses which are behind the main cat.
Long story, but those of you with 3.2 l cars will know about this.
It is the 2nd sensors that are normally there to measure the pre-cats, but when the pre-cats get tired you get an incessant EML light warning with a code 0420 (RH) or 0430 (LH). A prescribed solution is to move the secondary sensors to behind the main cats and thereby "fool" the system into thinking that the pre-cats are working well, when in fact both cats are cleaning the exhaust before it gets as far as the now repositioned sensors.
The problem is that until I parked up tonight the EML light was on. I left he car for a good few hours to cool down and then fitted a new sensor into the new boss further back and then disconnected my old sensor that is further forward.
Instantly the EML light dissapeared when I next ran the car. Great I thought, until I realised that the EML light doesn't even come on now, not even whilst I turn the ignition barrel round to the point where all the warning ights come on momentarily.
What is wrong? Has the EML bulb miraculously blown as I changed the sensor? Is there a fuse problem? Is that EML light even supposed to come on when you turn on the ignition?