Crokeefe 2.5GT

Code coming up is P0021, often related to the oil control valves or clogged banjo bolt filter. Want to make sure the filters not clogged and starving the turbo of oil. Car idles rough when not moving or during a stop light. Throws the CEL and will lose power while stopped or while driving, all of a sudden you can floor the gas and nothing will happen. After you pull off and restart it will run fine again for awhile. The throttle is also laggy like you can give it some gas and it won’t steadily accelerate, it will hesitate for a second and then almost jerks all at once. Could be a vacuum leak or boost leak issue. Also throws engine codes P2138 and P0420. Took it to shop and they said that by banjo bolts were probably bad and wanted 325 to replace them and they also said that if that didn’t fix the problem I might need a new turbo entirely. Any advise? Thanks