Can a restricted exhaust cause turbo overboost?

Yes, a restricted exhaust can cause turbo overboost. When the exhaust flow is restricted, it can lead to increased back pressure, which may prevent the turbocharger from properly regulating boost levels. As a result, the turbo may produce more boost than intended, potentially leading to overboost conditions and risking engine damage if not managed properly. Regular maintenance and monitoring of exhaust systems can help prevent such issues.