Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Dave W, How could you?

None of this has made any sense Doug. The sooty black tailpipe was from new. The AR flash cleaned it up. But the MoT has always been really marginal.

The bad running a year last October lasted for about 30 minutes in a trip which lasted 1hr 30. It suggested bad fuel, or electrical, but cleared completely after getting home, apart from the return of the sooty black tailpipe.

Going to the MoT, which is 55 miles gave a clean tailpipe, but the emissions were off the scale.Remember also that when I first added the AR exhaust, I was surprised that the sensor ahead of the cat was clean, but after the cat was black soot. That was similar when I changed the cat and the sensors this time. Getting back from the MoT, another 55 miles I have the sooty black tailpipe.

The upgraded standard ECU flash, which dealers hold, was to address the sharp throttle response. Now it's not quite as relaxed as it was but nowhere near the almost undrivable state it was in from new.

It makes no sense that the AR flash was a huge MoT fail. In theory the settings can't change and yet it was hopeless, and left me with the only option, to got back to the original settings. I knew that the exhaust alone gives a much crisper response, and that the flash really only adds cleaner revving at the top end. Coming home on real roads, there was no real difference.

I can only conclude that the standard flash provides good emissions up to the 2,500/3,000rpm MOT limit, and maybe after that goes rich. For me it's not worth the bother of paying again to have the AR flash, when the likelyhood is that it will not pass the next MoT. It's classic Morgan. The same models perform differently. We've seen that on models which suffer from throttle hang.