decat down pipe swap back to factory cat for nct question

Hi lads

Havin a nightmare ordered a cobra center section and 200 cell sports cat and they dont fit together without cutting and welding yo say im pissed is a understatement.
Ive sent them a email requesting a refund and am thinkin now to go decat and be done with the above..

If I go for a decat down pipe at nct time is it just a matter of swaping back on the factory cat?

Will this throw up a light on dash?
Will the car run right (considering it will be mapped for the decat)
Will the emmisions be thrown off for the test.(as maped for decat)
Anything else I need to know...

Cheers in advance again

If I go for a decat down pipe at nct time is it just a matter of swaping back on the factory cat?
Yes, but difficulty can be the swapping it out as the bolts may be seized after a prolonged amount of time on the car.

Will this throw up a light on dash? Possibly but this just reqires a resistor, if buying new, then they a good manufacturer will supply, if not then Ciaran will do it for you.
Will the car run right (considering it will be mapped for the decat). Yes, be fine, just don't give it full beans.
Will the emmisions be thrown off for the test.(as maped for decat). No, will pass with cat in, providing cat is in good condition of course.

Cheers Rob I couldn't have asked for a better reply than that karma +1
If its just the bolts that give the issues then that grand im sick trying to do the sports cat thing at this stage