Where do you live ? Get the car to a Tuner and have them street tune the car and see what they can tell from the data logs.
Or can you data log and send info to a Tuner ?
208,000miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.
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