I'm not doc, but if it's screwing with the mixture settings "on the fly", that might cause the surging problem he's talking about if it's faulty.

I know cars today have baro sensors (sort of).

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A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.