little problems

[Richie London]

good evening all.
i changed my rad at weekend, checked all hoses and could not see any more leaks. water in expansion tank has gone down about a litre since. do you think ive still got a leak somewhere or is it that when filled system back up i had an airlock in system and its cleared or could be somthing else. also when its warm its idle speed isnt steady, it goes up and down a little.
any ideas??
i did a paper clip test this afternoon, i had code 12 and 13 flashing. anything to worry about??

richie

[Marks DTM Calib]

Code 12 is start of code sequence.

13 is an O2 sensor open circuit, is the fault light on?

As for the water drop, its probably just the system self burping the air out.

[Richie London]

no lights on, it just flashed up on the test,  

[Marks DTM Calib]

Not a present code then so dont worry about it....