Passed the MOT ("Hauptuntersuchung") with the wrapped catalyst. My assessment: if you don't run the car (and its catalyst) on a track, you will probably not reach a sufficient temperature in the catalyst for it to work properly. I therefore recommend wrapping it for "normal" road use. However, at the beginning of the test, the not so hot catalyst "produced" CO2 that was through the roof. It took a few rev-ups until they came down sufficiently. The engine idle was still not perfect, but better than before - and it passed the test.
Robert, many thanks for taking the time to share your experiences.
Interesting theory of wrapping the cat to increase it`s temperature, which in your case Robert apparently assisted in passing the required emissions testing following previous failures.
I lack any real knowledge on emissions or their testing, but suspect that cats were designed to cut down aspects of emissions from the average usage of ICE across the population as a whole, thus I also suspect that track day usage and the likes may not have been considered by Morgan and other designers, when emission measurement test data was compiled to create acceptable measurable limits being agreed upon during the lifetime of ICE average usage..?
On the other hand given I suspect that ICE machines were designed to operate within reasonable expectations of average usage. That typed, I suspect Morgans and other modern-day potential Classics fitted with cats as the result of regulatory evolution, may not in the main(?) experience usage as might the average ICE, with perhaps many likely to be rarely used dependant on seasons of the year or weather conditions in general, thus all the more usual issues of vehicles likely laid-up for extended periods of time may suffer in all the usual ways dependant on circumstances...? That perhaps being the case, I suspect those with a mix of both cats and irregular usage, might benefit from wrapping the cat to raise it`s internal temp by some measure, perhaps, and thus increase it`s efficiency by some margin for/during the tests as you seem to have proved....?
