Engine management lights

About a week ago my engine management light came on and my car was acting like it was over heating but couldn't cool down.

Paid for an auto electrician to come out and hook up to diagnostic machine and he said the water pump needed to replacing this was done the same day.

managed to run about once pump replaced for about 1.5 days and all my engine management lights came back on again.

So took car to garage they hooked up to diagnostic machine and said they would need to replace lamba sensor 1, coil pack & cleaned breather pipes which were replaced in Dec due to being recalled by vauxhall.

Now only able to driving my car 5 miles and now I loose power am at my wits end as only had car 15mths and I have only done 11,000 in that time.

I was wondering in newer car when you fix the fault doesn't the ECU recognise the fault has been fixed or does it store the fault to it's memory and keep going into fault mode til ECU reset? As we have been able to do the above job ourselves.

Help?