Straight pipe on my OM616 turbo for the last 3 years,no noise gain at idle and cruise,slightly aggressive note at higher RPM while accelerating,EGT went down,operating temps went down,even under hard driving,temps stay under control,MPG went up,so did throttle response and acceleration,I also modded the air intake for inducing fresh air.I would definitely recommend this mod.

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99 Gurkha with OM616 IDI turbo

2015 Gurkha with OM616 DI turbo

2014 Rexton W with OM612 VGT