OK I have been able to get some answers which may help you make decisions as to what you want to do and keep you better informed as to the historical and actual facts relating to this issue. Certainly, I am sure, everyone would want to see your car pass its emissions test.
As I more-or-less knew Omex contracted with Morgan Motor Company ( Aero Racing) for the mapping and the supply of ECUs . Quite clearly they have no obligation towards end customers particularly as most of the elements involved were, and are, completely out of their control. The correct channel for any complaints and rectification is through the vehicle supplier. Unfortunately it is in our nature to expect a different kind of service from small companies but this is quite unfair. Imagine trying to get Bosch to resolve a problem with your BMW. Certainly Omex have the capacity for more flexibility than Bosch but any such extra service and assistance would be completely out of goodwill and would perhaps not even be 100% ethical from the point of view of the client, Morgan, who commissioned the work in the first place. Clearly, under these circumstances, any derogatory statements as to the quality of components or services provided by Omex would be completely counter productive.
Omex did not supply the engines, nor did they fit the cam change, and did not set the plug gaps (although they did specify them to be 0.9mm) but if the plugs have been changed (which they may have been in a three years old car) it is possible that they are not correct. Omex did not design the exhaust manifold and catalyst either. They are not happy with the claim (in effect from a competitor) that the ECU is not sophisticated enough. They say this is just nonsense and incorrect information.
Regarding the spark plugs; if anyone is using normal Duratec (Plus 4) spark plugs they will have serious issues as they are different lengths. The plugs fitted to Supersport were standard MX5 supplied by Mazda, I’m pretty sure Mazda know what plugs to fit! The engines did not come from America, (just an ill informed rumour), they were supplied direct from Japan via the UK parts importer.
As regards the ECU being locked, it isn’t. It is an OEM only ECU that does not have general access, just imagine asking Ford for access to one of their ECUs, I can be pretty sure of the reply they would give. However there is software that allows the dealer and owner enough access to setup the idle and TPS etc, this software was supplied to Morgan on CD for each car and should have been distributed with each car. Omex have that software if it is required but if you did not receive the CD with the car I would try to get a copy from Morgan. Naturally the first port of call should be the dealer from whom you purchased the car.
Omex are aware that there have been a few instances of the Supersport having an issue with MOT emissions and obviously they would like to find a solution. They will contact MMC to see if they are intending to do anything. However any solution Omex comes up with (unless of course the error is due to them) will have to be paid for by the owner and it will be up to them to take that up with MMC. However the cars are now three years old and out of warranty (a warranty that the customer agreed to by buying the vehicle) so it is probably not unreasonable for them to have some cost involved.
As an aside I am told that with a 200 cell cat it is quite usual to hold the engine at a higher RPM for a period before testing the emissions performance. This has no detrimental effect on anything and sometimes has to be done with normal production cars.
In my opinion, and I stress that it is only my opinion, Omex would be prepared to help if Morgan agreed and if approached in the correct way. My feeling is that this would be best handled through a dealer, such as, but not necessarily, Williams. Omex are perhaps better set up to deal with technical and experienced mechanics than they are with owners. They do support owners but would expect a certain level of technical expertise, availability of tools, etc. etc.