Couple questions to answer to see if we can figure out anything more here:
Vehicle: 2018 Lariat 3.0L V6 PSD
- Current mileage?
- Actual ODB code/number thrown? P0234?
- Status of 18E02 EGR By-Pass valve recall?
- Status of 20E04 EGR By-Pass valve recall?
- Are you indicating that your turbo has previously been replaced also?
- If so, can you provide some background/history behind this previous failure?
- Was the turbo replaced under warranty?
- Original owner? Or did you buy used?
No guarantees on diagnosis but we can flesh things out further here.
2018 Model year = your truck was subject to both 18E02 and 20E04 By-Pass valve recalls
=> Hence why I am asking for the recall status for both recalls
=> If you are unsure, ask your dealer for a VIN-specific OASIS report
=> OASIS report will contain any-and-all recall work Ford has done on your truck
I think the only other P0234 we have seen here was Post
#56 from @flharrison in the infamous
START HERE: Any owners affected by FSA 18E02 (EGR By-pass valve replacement) thread, which was clouded by being at the same time as the 18E02 recalls. If you follow his updates in that thread, I think they found a loose pin in the VGT in the turbo and some form of exhaust leak.
Welcome to the forums = wish your intro could have been on a better note...