AdamKu

I have two different fault codes that I can not sort out so hoping for getting help from more experienced owners. the first one is for the o2 sensor pre cat. Came on randomly and stayed on. When cleared it does not come back immediately, but after 2-3 start ups. Had the sensor changed yesterday and the fault still persists. The fault code is for heater circuit so thought changing sensor will get it sorted, but now a bit stuck - what to check next and what look for? next one is for the defroster/temperature flap. Had a fault for temperature motor before that one so ended up replacing both motors. Put them back in and the faults seem to dissapear, but this one cane back and for some reason the climatronic would not go through basic settings. was there something that I messed up when fitting motors back? Do they need to go into a certain positions of flaps acutator? As I just put them back and assumed the flaps in center console did not move ? So looking dor advice on what I did wrong or what to check? thanks in advance