So I held the neg cable onto the pos post with the pos cable still connected for about 5-6 seconds with the ign on as suggested.
After reconnecting, the idle was high but came back to normal pretty quickly.
windows needed a reset

I then let it idle for 2-3 mins with the air and rear defrost on
A further 2min idle in Drive position (footbrake on!)
After connecting the code reader to check the monitors they were exactly the same as before, everything was ready except the "cat not ready" monitor.
I guess my question is that will all the monitors reset (except the cat) just from idling a total of about 5 mins or am I still just seeing the old readings?
Thanks

 

Yes, it did reset. Did you get a P1000 indicating internal testing not complete? You will need to go through several drive cycles before it will display P1111 indicating self test complete. Sometimes it's necessary to go through a complicated drive cycle :Drive Cycle.pdf

 

Thanks, yes but the P1000 was there before, due to a battery swap. Been trying for months and a thousand miles to get rid of the cat not ready which wasn't there before the battery swap.
I love it when people say "just drive for 5 mins at between 1700-2500 rpm. Drive cycles up the wazoo. Nothing works!

 

Drive cycles repeated is unfortunately the only real way to set all monitors. If you have done the drive cycles and still can't get the monitor for the cats to set you are going to have to look for codes pending. If your reader can't give codes pending them try to find a source for one that can. You may have a minor problem that won't set a code based on repeating the condition but still won't clear the code.
Since you know it is the cat monitor I would recommend disconnecting the sensors one at a time and cleaning the contacts and reconnecting. Also visually inspect each of the sensor cables for any insulation damage. Damaged insulation on the connector cable will give an occasional fault but not a repeatable fault. Offhand I don't remember for sure but I think the fault has to repeat 4 or 5 times to throw a code and illuminate the check engine light.

 

Thank you! Do you know which sensors? How many and their locations?
Alan