Fabia MKI going into limp mode

Hello!

I've been having a recurring issue with my car going into limp mode at (what seem to be) random times. It drives fine, and if you stop the car and turn it off and back on again, it carries on as normal.

It started happening a couple of years ago but would only happen a few times within a week and then might not happen again for another 6 months or more. 

We've mentioned it when the car has been serviced but the garage has always said they can't find evidence of any issue. However, recently our check engine light came on and the car was dropping into limp mode much more frequently; probably every second or third time driving it no matter the journey distance/conditions. 

We took the car back to the garage, as it had just been serviced, and they cleared a fault with the MAP sensor and mentioned that my ignition coils needed changing. We had just changed the spark plugs so I had the ignition coils done, left, drove for a week and then the issue returned along with the check engine light.

I contacted the garage again and they said to bring it back. This time the issue with the sensor had returned and was reporting an air leak, but apparently they couldn't detect an air leak so put the issue down to a faulty MAP sensor. I changed the sensor with the garage and, again, drove the car for a few days before it dropped into limp mode and the check engine light returned.

I got the impression from the garage that if the sensor didn't fix the issue, then they would be at a loss as there were no other fault codes/visible issues at the time. Not trying to badmouth them either as they've been very good with everything.

I'm here to ask if anyone has any advice or has experienced a similar issue, so any help will be greatly appreciated. I apologise if I've left out any important info and I will provide it if needed.

Car info:

Skoda Fabia MKI

1.4 Litre

2004

Petrol

Automatic

Approx 60,000 miles