emission control light on 2019 Q5

Any European repair shop can run diagnostics and most likely fix the problem without costing you an arm and both legs. However if it is still under a warranty then you must take it the dealer.

As long as the light is not flashing then it should be ok to drive it.

If it's the gold/yellow CEL, just have this addressed somewhat soon. If red, have it looked at before you drive at high speeds, so Austin to Dallas, a distance I've driven many times, should be fine as long as you stay under seventy mph. If the CEL is flashing, don't drive at all. Have a local Audi mechanic/dealer diagnose this and fix it.

A flashing check engine light (CEL) means the engine is misfiring and damaging the catalytic converter. You should not drive it if it's flashing, catalytic converters aren't cheap! If the light is on steady and the vehicle appears to be running fine you'll be ok to drive it. One thing you can do in the meantime is remove and reinstall the gas cap. If it was not put on properly the last time you got gas the check engine light will come on. However, that's just one of over one hundred things that will make the light come on. Hope that helps! Jim