I have a Mercedes C250 estate (2011) When I exceed certain revs the engine warning light goes on and the car looses power and goes into Limp Home. I've had diagnostics done, they showed a problem with DPF (had cleaned) pressure sensor (had replaced) but the problem persists. A garage has told me they suspect that the intake manifold has a hole or is warped. How much would it get to have this replaced and can anyone recommend a good place to have this done in West London. Also, does it make it cheaper if I supply parts myself? Thanks!