No that's not a check valve. The problem is that the ECU is seeing boost. Even with a 2 or 3 bar map sensor, the Map sensor will detect the pressure and the ECU is still going to see boost and throw a CEL. A check valve basically ensures that the MAP sensor doesn't see the pressure rise in the intake manifold, so the ECU doesn't see the boost.
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2015 Ford Mustang GT Fastback - Ingot Silver - 6M - Performance Package - Gibson Catback, JLT CAI, FR 47lb injectors, BAMA E85 tune, Eibach Sportline, BMR wheel hop kit, UPR oil separator, Steeda shifter bushing/bracket
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