[Sgtslaughterrrr]

Anybody have any ideas whats causing my high idle, heres a little info on car i purchased car with 67mm single turbo looks to be custom made, turbo has a intercooler but no blow off valve, im getting oil in turbo piping and can see oil on my maf, my check engine light is on, today i pulled the maf of and cleaned it with carb cleaner and engine code went off but car will still idle around 1100 rpm for awhile before returing to 750 normal idle, engine will surge to 2000 rpm when coming out of gear at redlights sometimes and then back down to 1100 rpm, when engine is cold it will start up like normal high idle till warm and to a normal idle of 750rpm. Code is po507, po113 and po102 but clears when maf is clean of oil, but idle still high when driving in town, wideband meter reads 11.5 on wot and 12 to 13 when high way speeds and sometimes highway speeds will read 14 to 15 on wideband something is wrong, gas mileage sucks, im going to rebuild turbo and install blow off valve next week, maybe that wiill fix my oil in turbo line problem, is there another sensor that could be oiled up thats causeing high idle? Running 8psi on turbo , willbe tring to clean up someone elses build, car has 14000 miles ss m6 car thanks