2002 Skoda Octavia Slow accerlation

I am using Skoda 2.0 Ambiente. From past few its accerlation has dropped. Its like very heavy to drive it. My techie replaced spark plugs, fuel filters and checked fuel pump, cleaned injectors but still there seems to be no improvement. Is there any chance that its related to Injector coil or its housing?? Its not going beyond 70mph while prior i used to drive at around 115mph.

Please help out?