Mine did that at ~130,000 mi. The manifold is uner $200 from the dealer and a simple job to replace.

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Lenny

There are only three sports: bullfighting, motor racing and mountaineering; all the rest are merely games. --Ernest Hemingway

'10 GL550/'04 BMW 545/'99 BMW 323/'98 ML320/'87 VW GTI (race)