ok so i have a few concerns.

My car takes about 20mins of driving to get upto temp, when i say upto temp i mean 70-80deg, i only see it at 90deg when im constantly driving on the motorway.

All the vents blow hot air as they should except for the foot vents! even when i direct all air to blow through the foot vents i seems considerably cooler,
it will only blow luke warm air when i manage to get the car upto 90deg, if the car doesn't reach 90deg im left with feet like ice blocks.

Ive noticed all this over the past couple of days since the temps are hitting freezing outside.

i have the supplement heater set to auto.

i assume deleting the egr will have an effect vehicle temps? could this be the cause? i cant see how, as its just the foot vents that are the issue and not all the vents.

the car has no error codes.

could it possibly be the engine thermostat at fault?