If I were to build a car using all components from a J reg sierra, except the engine, which came from a year 2000 mondeo, would it....

1. Be tested as needing a cat?

2. Get a J registration?

3. When it came to MOT time, need a cat?

It would need a cat for SVA regardless.

You could change the engine in the sierra to the mondeo one (hypothetically of course) then you have only used one donor and will get an age related plate.

MOT wouldnt need a cat if it was on a J plate.

Fun stuff eh?

On the other hand just get a Q plate and get a visual smoke only test at MOT.

"On the other hand just get a Q plate and get a visual smoke only test at MOT. "

There's a 'clamp down' coming in in Northern Ireland MOT centres and apparently this might not hold true anymore - they're talking about doing it on engine age as for SVA.
It's likely that'll also happen at some point on the mainland. I have an MOT for the end of the month under the new regs, I'll post my experiences.

The legal reqs I posted here:-
http://www.locostbuilders.co.uk/viewthread.php?tid=39314

I only hope I'm wrong!

Firstly - how the **!!k did I become logged out and lose a *&!t load of text

Flakky - You recon they'd spot a zetec blacktop as needin a cat?? - regardless of whether it was on the J reg sierra V5 (paperwork exercise or not)?

If the car then got a J plate with the zetec, then it wouldn't need a cat for subsequent MOT's cos it would be a J plate??

I'd rather change the I4 engine I've got in it now, before the SVA, but don't want to have it subject to needing a cat for later MOT's.

Failsafe is to leave the I4 DOHC in till after SVA, then change it?