New To Site NEED HELP!!

HI Iam asking for advice, I have a skoda 2008 VRS i have had this car for 13 years looking after it, but as it as now reached 150000 miles i am now had to have work done on it, issue i have is the after replacing wiring harness on injectors, replacing vac unit, valves & gasket also replaced faulty throttle body, my car then had an issue with the exhaust pressure sensor. Now it as been remapped and sensores turned of BUT motorway driving is awful as it wont drive well at 70mph any ideas of how to fix this . thankyou