[doughboy]

Yes partly.

By same fitment I mean same physical dimensions and end fittings. Yes OPF cars need the post-CAT pressure bleed line which is same as OPF M4 (no OPF M3 built). The OPF pressure sensor gubbins is on the car not the DP and connects to the pressure bleed line on the DP with a rubber hose.

...But If you a removing OPF then you need to code out checks, so you don't need the bleed line on the DP either...

In the UK there is no emissions test for OPF, only visual inspection and a check for no CELs. If you have no CELs then you will pass. Unless the MOT guy is a) an M2C expert and b) a twat, you will never fail for missing OPF unless it is an obvious botch job or bypass pipes etc.

The MOT petrol emissions test is only for CAT function, lambda etc. not particulates.

Most other manufacturers are integrating their OPFs into the main DP canister along with the CAT so again any MOT tester would have to know that M2C has an external OPF.

The mid silencer looks very much like an OPF might do too.