Does the EGR Valve Assembly need to be replaced or can just the EGR sensor be replaced and what type of service facility can replace this part?

Just about any repair place and usually just the egr valve itsself can b replaced

Yes,the egr valve can be replaced. you did not specify what year,make model or the engine size,but the egr valve can be replaced .not an assembly. just the egr valve. do not be scammed! suggest you call several parts places,autozone.com or advance auto,com call several garages for estimates.you will find that the part costs quite a bit. i replaced one the other day on an 89 blazer for $25.00 but customer supplied part.took 20minutes to replace. some take longer than others. that's why i tell you to call several garages to get labor only price.if they supply the part,they will mark up the price.i do. i have to take time to go get part,then replace it also. the part cost,the labor cost. if you pay $90.00 for the part,which may be your case.the garage is going to charge you twice what the part costs to replace it. call ahead before you commit. price match with auto parts stores. if you find it cheaper somewhere else,don't be afraid to tell the other parts store so. most cases,they will match the other stores price. and so it goes with the labor. do not be scared to ASK questions and compare labor prices.hope this helps and if so,let me know. thank you for choosing fixya.com we are here 24/7 7days/week