Scooba-roo

iTrader: (1)

I've just got back from the Stealers where my car just failed an MOT test due to emissions. CO and Lamda failed, tried it again after using Injector cleaner and a good run, tested it hot and it still failed. It's a MY00 classic.

I've recently put in a new MAF sensor and a new Lamda although this was a universal one and not the direct replacement part. It passed last year with no issues, but since then I've added a K&N performance filter and a Walbro fuel pump. I haven't had the engine remapped. Since I changed the sensors I've had no running problems, and I did reset the ECU as well. The car is running on a standard exhaust which is now 10 years old, is it likely that a leak could cause an emissions failure? CO is at 2.3% which is a lot higher than the 0.3% allowed.
or is is likely to be more serious... Turbo failure? I'm getting a whine when the car is driven hard, it seems to relate to engine revs as when the clutch is dipped it goes away, but I thought that this might be the diff/gearbox. Do I need to remap with the mods I've made?

Any ideas or help would be much appreciated.

Thanks