For those with the 335i (N54), o-rings for the turbo connections are available from BMW (Part# 11427558936). E90 E91 E92 E93: 316i, 318i, 320i, 323i, 325i, 328i, 330i, 335i. But don't waste money buying a new sensor or unnecessarily replacing hose assemblies, all of which can last well beyond 10 years/150,000 miles.
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